Author: Michael R Sweet
Keywords: Programming

# CUPS 3.0 Programming Manual

Michael R Sweet

Copyright © 2021-2026 by OpenPrinting. All Rights Reserved.

## Contents

- Introduction
  - Guidelines
  - Terms Used in This Document
  - Compiling Programs That Use the CUPS API
- Working with Destinations
  - Finding Available Destinations
  - Basic Destination Information
  - Detailed Destination Information
  - Submitting a Print Job
- Sending IPP Requests
  - Connecting to the Scheduler or Printer
  - Creating an IPP Request
  - Sending the IPP Request
  - Processing the IPP Response
- Authentication and Authorization
  - Authentication Using Passwords
  - Authorization using OAuth/OpenID Connect
- IPP Data File API
  - Creating an IPP Data File
  - Reading a Data File
  - Variables
  - Writing IPP Data Files
- Migrating Code from CUPS 2.x and Earlier
  - General Changes
  - Specific API Changes
  - Removed Functions and Types
  - Renamed Functions and Types
- Functions
  - cupsAddDest
  - cupsAddDestMediaOptions
  - cupsAddIntegerOption
  - cupsAddOption
  - cupsAreCredentialsValidForName
  - cupsArrayAdd
  - cupsArrayAddStrings
  - cupsArrayClear
  - cupsArrayDelete
  - cupsArrayDup
  - cupsArrayFind
  - cupsArrayGetCount
  - cupsArrayGetCurrent
  - cupsArrayGetElement
  - cupsArrayGetFirst
  - cupsArrayGetIndex
  - cupsArrayGetInsert
  - cupsArrayGetLast
  - cupsArrayGetNext
  - cupsArrayGetPrev
  - cupsArrayGetUserData
  - cupsArrayInsert
  - cupsArrayNew
  - cupsArrayNewStrings
  - cupsArrayRemove
  - cupsArrayRestore
  - cupsArraySave
  - cupsCancelDestJob
  - cupsCharsetToUTF8
  - cupsCheckDestSupported
  - cupsCloseDestJob
  - cupsConcatString
  - cupsCondBroadcast
  - cupsCondDestroy
  - cupsCondInit
  - cupsCondWait
  - cupsConnectDest
  - cupsCopyCredentials
  - cupsCopyCredentialsKey
  - cupsCopyCredentialsPublicKey
  - cupsCopyCredentialsRequest
  - cupsCopyDest
  - cupsCopyDestConflicts
  - cupsCopyDestInfo
  - cupsCopyString
  - cupsCreateCredentials
  - cupsCreateCredentialsRequest
  - cupsCreateDestJob
  - cupsCreateTempFd
  - cupsCreateTempFile
  - cupsDNSSDAssembleFullName
  - cupsDNSSDBrowseDelete
  - cupsDNSSDBrowseGetContext
  - cupsDNSSDBrowseNew
  - cupsDNSSDCopyComputerName
  - cupsDNSSDCopyHostName
  - cupsDNSSDDecodeTXT
  - cupsDNSSDDelete
  - cupsDNSSDGetConfigChanges
  - cupsDNSSDNew
  - cupsDNSSDQueryDelete
  - cupsDNSSDQueryGetContext
  - cupsDNSSDQueryNew
  - cupsDNSSDResolveDelete
  - cupsDNSSDResolveGetContext
  - cupsDNSSDResolveNew
  - cupsDNSSDSeparateFullName
  - cupsDNSSDServiceAdd
  - cupsDNSSDServiceDelete
  - cupsDNSSDServiceGetContext
  - cupsDNSSDServiceGetName
  - cupsDNSSDServiceNew
  - cupsDNSSDServicePublish
  - cupsDNSSDServiceSetLocation
  - cupsDirClose
  - cupsDirOpen
  - cupsDirRead
  - cupsDirRewind
  - cupsDoAuthentication
  - cupsDoFileRequest
  - cupsDoIORequest
  - cupsDoRequest
  - cupsEncodeOption
  - cupsEncodeOptions
  - cupsEncodingString
  - cupsEncodingValue
  - cupsEnumDests
  - cupsFileClose
  - cupsFileEOF
  - cupsFileFind
  - cupsFileFlush
  - cupsFileGetChar
  - cupsFileGetConf
  - cupsFileGetLine
  - cupsFileGets
  - cupsFileIsCompressed
  - cupsFileLock
  - cupsFileNumber
  - cupsFileOpen
  - cupsFileOpenFd
  - cupsFilePeekChar
  - cupsFilePrintf
  - cupsFilePutChar
  - cupsFilePutConf
  - cupsFilePuts
  - cupsFileRead
  - cupsFileRewind
  - cupsFileSeek
  - cupsFileStderr
  - cupsFileStdin
  - cupsFileStdout
  - cupsFileTell
  - cupsFileUnlock
  - cupsFileWrite
  - cupsFindDestDefault
  - cupsFindDestReady
  - cupsFindDestSupported
  - cupsFinishDestDocument
  - cupsFormDecode
  - cupsFormEncode
  - cupsFormatString
  - cupsFormatStringv
  - cupsFreeDestInfo
  - cupsFreeDests
  - cupsFreeJobs
  - cupsFreeOptions
  - cupsGetClock
  - cupsGetCredentialsExpiration
  - cupsGetCredentialsInfo
  - cupsGetCredentialsTrust
  - cupsGetDefault
  - cupsGetDest
  - cupsGetDestMediaByIndex
  - cupsGetDestMediaByName
  - cupsGetDestMediaBySize
  - cupsGetDestMediaCount
  - cupsGetDestMediaDefault
  - cupsGetDestWithURI
  - cupsGetDests
  - cupsGetEncryption
  - cupsGetError
  - cupsGetErrorString
  - cupsGetFd
  - cupsGetFile
  - cupsGetIntegerOption
  - cupsGetJobs
  - cupsGetNamedDest
  - cupsGetOption
  - cupsGetPassword
  - cupsGetRand
  - cupsGetResponse
  - cupsGetServer
  - cupsGetUser
  - cupsGetUserAgent
  - cupsHMACData
  - cupsHashData
  - cupsHashString
  - cupsJSONAdd
  - cupsJSONDelete
  - cupsJSONExportFile
  - cupsJSONExportString
  - cupsJSONFind
  - cupsJSONGetChild
  - cupsJSONGetCount
  - cupsJSONGetKey
  - cupsJSONGetNumber
  - cupsJSONGetParent
  - cupsJSONGetSibling
  - cupsJSONGetString
  - cupsJSONGetType
  - cupsJSONImportFile
  - cupsJSONImportString
  - cupsJSONImportURL
  - cupsJSONNew
  - cupsJSONNewKey
  - cupsJSONNewNumber
  - cupsJSONNewString
  - cupsJWTDelete
  - cupsJWTExportString
  - cupsJWTGetAlgorithm
  - cupsJWTGetClaimNumber
  - cupsJWTGetClaimString
  - cupsJWTGetClaimType
  - cupsJWTGetClaimValue
  - cupsJWTGetClaims
  - cupsJWTGetHeaderNumber
  - cupsJWTGetHeaderString
  - cupsJWTGetHeaderType
  - cupsJWTGetHeaderValue
  - cupsJWTGetHeaders
  - cupsJWTHasValidSignature
  - cupsJWTImportString
  - cupsJWTLoadCredentials
  - cupsJWTMakePrivateKey
  - cupsJWTMakePublicKey
  - cupsJWTNew
  - cupsJWTSetClaimNumber
  - cupsJWTSetClaimString
  - cupsJWTSetClaimValue
  - cupsJWTSetHeaderNumber
  - cupsJWTSetHeaderString
  - cupsJWTSetHeaderValue
  - cupsJWTSign
  - cupsLangAddStrings
  - cupsLangDefault
  - cupsLangFind
  - cupsLangFormatString
  - cupsLangGetEncoding
  - cupsLangGetName
  - cupsLangGetString
  - cupsLangIsRTL
  - cupsLangLoadStrings
  - cupsLangPrintf
  - cupsLangPuts
  - cupsLangSetDirectory
  - cupsLangSetLocale
  - cupsLocalizeDestMedia
  - cupsLocalizeDestOption
  - cupsLocalizeDestValue
  - cupsLocalizeNotifySubject
  - cupsLocalizeNotifyText
  - cupsMutexDestroy
  - cupsMutexInit
  - cupsMutexLock
  - cupsMutexUnlock
  - cupsOAuthClearTokens
  - cupsOAuthCopyAccessToken
  - cupsOAuthCopyClientId
  - cupsOAuthCopyRefreshToken
  - cupsOAuthCopyUserId
  - cupsOAuthGetAuthorizationCode
  - cupsOAuthGetClientId
  - cupsOAuthGetDeviceGrant
  - cupsOAuthGetJWKS
  - cupsOAuthGetMetadata
  - cupsOAuthGetTokens
  - cupsOAuthGetUserId
  - cupsOAuthMakeAuthorizationURL
  - cupsOAuthMakeBase64Random
  - cupsOAuthSaveClientData
  - cupsOAuthSaveTokens
  - cupsParseOptions
  - cupsPutFd
  - cupsPutFile
  - cupsRWDestroy
  - cupsRWInit
  - cupsRWLockRead
  - cupsRWLockWrite
  - cupsRWUnlock
  - cupsRasterClose
  - cupsRasterGetErrorString
  - cupsRasterInitHeader
  - cupsRasterOpen
  - cupsRasterOpenIO
  - cupsRasterReadHeader
  - cupsRasterReadPixels
  - cupsRasterWriteHeader
  - cupsRasterWritePixels
  - cupsReadResponseData
  - cupsRemoveDest
  - cupsRemoveOption
  - cupsSaveCredentials
  - cupsSendRequest
  - cupsSetClientCredentials
  - cupsSetDefaultDest
  - cupsSetDests
  - cupsSetEncryption
  - cupsSetOAuthCB
  - cupsSetPasswordCB
  - cupsSetServer
  - cupsSetServerCredentials
  - cupsSetUser
  - cupsSetUserAgent
  - cupsSignCredentialsRequest
  - cupsStartDestDocument
  - cupsThreadCancel
  - cupsThreadCreate
  - cupsThreadDetach
  - cupsThreadWait
  - cupsUTF32ToUTF8
  - cupsUTF8ToCharset
  - cupsUTF8ToUTF32
  - cupsWriteRequestData
  - httpAcceptConnection
  - httpAddrClose
  - httpAddrConnect
  - httpAddrCopyList
  - httpAddrFreeList
  - httpAddrGetFamily
  - httpAddrGetLength
  - httpAddrGetList
  - httpAddrGetPort
  - httpAddrGetString
  - httpAddrIsAny
  - httpAddrIsEqual
  - httpAddrIsLocalhost
  - httpAddrListen
  - httpAddrLookup
  - httpAddrSetPort
  - httpAssembleURI
  - httpAssembleURIf
  - httpAssembleUUID
  - httpClearCookie
  - httpClearFields
  - httpClose
  - httpConnect
  - httpConnectAgain
  - httpConnectURI
  - httpCopyPeerCredentials
  - httpDecode64
  - httpEncode64
  - httpFieldValue
  - httpFlush
  - httpFlushWrite
  - httpGetActivity
  - httpGetAddress
  - httpGetAuthString
  - httpGetBlocking
  - httpGetContentEncoding
  - httpGetCookie
  - httpGetCookieValue
  - httpGetDateString
  - httpGetDateTime
  - httpGetEncryption
  - httpGetError
  - httpGetExpect
  - httpGetFd
  - httpGetField
  - httpGetHostname
  - httpGetKeepAlive
  - httpGetLength
  - httpGetPending
  - httpGetReady
  - httpGetRemaining
  - httpGetSecurity
  - httpGetState
  - httpGetStatus
  - httpGetSubField
  - httpGetVersion
  - httpGets
  - httpInitialize
  - httpIsChunked
  - httpIsEncrypted
  - httpPeek
  - httpPrintf
  - httpRead
  - httpReadRequest
  - httpResolveHostname
  - httpResolveURI
  - httpSeparateURI
  - httpSetAuthString
  - httpSetBlocking
  - httpSetCookie
  - httpSetDefaultField
  - httpSetEncryption
  - httpSetExpect
  - httpSetField
  - httpSetKeepAlive
  - httpSetLength
  - httpSetTimeout
  - httpShutdown
  - httpStateString
  - httpStatusString
  - httpURIStatusString
  - httpUpdate
  - httpWait
  - httpWrite
  - httpWriteRequest
  - httpWriteResponse
  - ippAddBoolean
  - ippAddBooleans
  - ippAddCollection
  - ippAddCollections
  - ippAddCredentialsString
  - ippAddDate
  - ippAddInteger
  - ippAddIntegers
  - ippAddOctetString
  - ippAddOutOfBand
  - ippAddRange
  - ippAddRanges
  - ippAddResolution
  - ippAddResolutions
  - ippAddSeparator
  - ippAddString
  - ippAddStringf
  - ippAddStringfv
  - ippAddStrings
  - ippAttributeString
  - ippContainsInteger
  - ippContainsString
  - ippCopyAttribute
  - ippCopyAttributes
  - ippCopyCredentialsString
  - ippCreateRequestedArray
  - ippDateToTime
  - ippDelete
  - ippDeleteAttribute
  - ippDeleteValues
  - ippEnumString
  - ippEnumValue
  - ippErrorString
  - ippErrorValue
  - ippFileClose
  - ippFileDelete
  - ippFileExpandVars
  - ippFileGetAttribute
  - ippFileGetAttributes
  - ippFileGetFilename
  - ippFileGetLineNumber
  - ippFileGetVar
  - ippFileNew
  - ippFileOpen
  - ippFileRead
  - ippFileReadCollection
  - ippFileReadToken
  - ippFileRestorePosition
  - ippFileSavePosition
  - ippFileSetAttributes
  - ippFileSetGroupTag
  - ippFileSetVar
  - ippFileSetVarf
  - ippFileWriteAttributes
  - ippFileWriteComment
  - ippFileWriteToken
  - ippFileWriteTokenf
  - ippFindAttribute
  - ippFindNextAttribute
  - ippGetBoolean
  - ippGetCollection
  - ippGetCount
  - ippGetDate
  - ippGetFirstAttribute
  - ippGetGroupTag
  - ippGetInteger
  - ippGetLength
  - ippGetName
  - ippGetNextAttribute
  - ippGetOctetString
  - ippGetOperation
  - ippGetPort
  - ippGetRange
  - ippGetRequestId
  - ippGetResolution
  - ippGetState
  - ippGetStatusCode
  - ippGetString
  - ippGetValueTag
  - ippGetVersion
  - ippNew
  - ippNewRequest
  - ippNewResponse
  - ippOpString
  - ippOpValue
  - ippRead
  - ippReadFile
  - ippReadIO
  - ippRestore
  - ippSave
  - ippSetBoolean
  - ippSetCollection
  - ippSetDate
  - ippSetGroupTag
  - ippSetInteger
  - ippSetName
  - ippSetOctetString
  - ippSetOperation
  - ippSetPort
  - ippSetRange
  - ippSetRequestId
  - ippSetResolution
  - ippSetState
  - ippSetStatusCode
  - ippSetString
  - ippSetStringf
  - ippSetStringfv
  - ippSetValueTag
  - ippSetVersion
  - ippStateString
  - ippTagString
  - ippTagValue
  - ippTimeToDate
  - ippValidateAttribute
  - ippValidateAttributes
  - ippWrite
  - ippWriteFile
  - ippWriteIO
  - pwgFormatSizeName
  - pwgInitSize
  - pwgMediaForLegacy
  - pwgMediaForPPD
  - pwgMediaForPWG
  - pwgMediaForSize
- Data Types
  - cups_acopy_cb_t
  - cups_adv_t
  - cups_afree_cb_t
  - cups_ahash_cb_t
  - cups_array_cb_t
  - cups_array_t
  - cups_bool_t
  - cups_cert_san_cb_t
  - cups_cond_t
  - cups_credpurpose_t
  - cups_credtype_t
  - cups_credusage_t
  - cups_cspace_t
  - cups_cut_t
  - cups_dentry_t
  - cups_dest_cb_t
  - cups_dest_flags_t
  - cups_dest_t
  - cups_dinfo_t
  - cups_dir_t
  - cups_dnssd_browse_cb_t
  - cups_dnssd_error_cb_t
  - cups_dnssd_flags_t
  - cups_dnssd_query_cb_t
  - cups_dnssd_query_t
  - cups_dnssd_resolve_cb_t
  - cups_dnssd_resolve_t
  - cups_dnssd_browse_t
  - cups_dnssd_service_cb_t
  - cups_dnssd_service_t
  - cups_dnssd_t
  - cups_edge_t
  - cups_utf32_t
  - cups_file_t
  - cups_job_t
  - cups_jog_t
  - cups_json_t
  - cups_jtype_t
  - cups_jwa_t
  - cups_jws_format_t
  - cups_jwt_t
  - cups_lang_t
  - cups_media_flags_t
  - cups_media_t
  - cups_mediapos_t
  - cups_mutex_t
  - cups_oauth_cb_t
  - cups_ogrant_t
  - cups_option_t
  - cups_order_t
  - cups_orient_t
  - cups_page_header_t
  - cups_password_cb_t
  - cups_ptype_t
  - cups_raster_mode_t
  - cups_raster_t
  - cups_rwlock_t
  - cups_thread_func_t
  - cups_thread_key_t
  - cups_thread_t
  - cups_whichjobs_t
  - http_addr_t
  - http_addrlist_t
  - http_encoding_t
  - http_encryption_t
  - http_field_t
  - http_keepalive_t
  - http_resolve_cb_t
  - http_resolve_t
  - http_state_t
  - http_status_t
  - http_t
  - http_timeout_cb_t
  - http_trust_t
  - http_uri_coding_t
  - http_uri_status_t
  - http_version_t
  - ipp_attribute_t
  - ipp_copy_cb_t
  - ipp_dstate_t
  - ipp_fattr_cb_t
  - ipp_ferror_cb_t
  - ipp_file_t
  - ipp_ftoken_cb_t
  - ipp_io_cb_t
  - ipp_jstate_t
  - ipp_op_t
  - ipp_orient_t
  - ipp_pstate_t
  - ipp_quality_t
  - ipp_res_t
  - ipp_rstate_t
  - ipp_sstate_t
  - ipp_state_t
  - ipp_t
  - ipp_uchar_t
  - pwg_media_t
- Structures
  - cups_dentry_s
  - cups_dest_s
  - cups_job_s
  - cups_media_s
  - cups_option_s
  - cups_page_header_s
  - http_addrlist_s
  - pwg_media_s
- Enumerations
  - cups_adv_e
  - cups_bool_e
  - cups_credpurpose_e
  - cups_credtype_e
  - cups_credusage_e
  - cups_cspace_e
  - cups_cut_e
  - cups_dest_flags_e
  - cups_dnssd_flags_e
  - cups_dnssd_rrtype_e
  - cups_edge_e
  - cups_encoding_e
  - cups_jog_e
  - cups_jtype_e
  - cups_jwa_e
  - cups_jws_format_e
  - cups_media_flags_e
  - cups_mediapos_e
  - cups_ogrant_e
  - cups_order_e
  - cups_orient_e
  - cups_ptype_e
  - cups_raster_mode_e
  - cups_whichjobs_e
  - http_encoding_e
  - http_encryption_e
  - http_field_e
  - http_keepalive_e
  - http_resolve_e
  - http_state_e
  - http_status_e
  - http_trust_e
  - http_uri_coding_e
  - http_uri_status_e
  - http_version_e
  - ipp_dstate_e
  - ipp_finishings_e
  - ipp_jstate_e
  - ipp_op_e
  - ipp_orient_e
  - ipp_pstate_e
  - ipp_quality_e
  - ipp_res_e
  - ipp_rstate_e
  - ipp_sstate_e
  - ipp_state_e
  - ipp_status_e
  - ipp_tag_e

> Please file issues on Github to provide feedback on this document.

## Introduction

CUPS 3.0 provides the "cups3" library to talk to the different parts of CUPS and with Internet Printing Protocol (IPP) printers. The "cups" library functions are accessed by including the `<cups/cups.h>` header.

CUPS is based on the Internet Printing Protocol ("IPP"), which allows clients (applications) to communicate with a server (the scheduler, printers, etc.) to get a list of destinations, send print jobs, and so forth. You identify which server you want to communicate with using a pointer to the opaque structure `http_t`. The `CUPS_HTTP_DEFAULT` constant can be used when you want to talk to the default CUPS spooler.

### Guidelines

When writing software that uses the "cups" library:

- Do not use undocumented, private, or deprecated APIs,

- Do not rely on pre-configured printers,

- Do not assume that printers support specific features or formats, and

- Do not rely on implementation details.

CUPS is designed to insulate users and developers from the implementation details of printers and file formats. The goal is to allow an application to supply a print file in a standard format with the user intent ("print four copies, two-sided on A4 media, and staple each copy") and have the printing system manage the printer communication and format conversion needed.

Similarly, printer and job management applications can use standard query operations to obtain the status information in a common, generic form and use standard management operations to control the state of those printers and jobs.

### Terms Used in This Document

A Destination is a printer or print queue that accepts print jobs. A Print Job is a collection of one or more documents that are processed by a destination using options supplied when creating the job. A Document is a file (JPEG image, PDF file, etc.) suitable for printing. An Option controls some aspect of printing, such as the media used. Media is the sheets or roll that is printed on. An Attribute is an option encoded for an Internet Printing Protocol (IPP) request.

### Compiling Programs That Use the CUPS API

The CUPS libraries can be used from any C, C++, or Objective C program. The method of compiling against the libraries varies depending on the operating system and installation of CUPS. The following sections show how to compile a simple program (shown below) in two common environments.

The following simple program lists the available destinations:

    #include <stdio.h>
    #include <cups/cups.h>

    bool print_dest(void *cb_data, unsigned flags, cups_dest_t *dest)
    {
      if (dest->instance)
        printf("%s/%s\n", dest->name, dest->instance);
      else
        puts(dest->name);

      return (true);
    }

    int main(void)
    {
      cupsEnumDests(CUPS_DEST_FLAGS_NONE, 1000, NULL, 0, 0, print_dest, NULL);

      return (0);
    }

#### Compiling with Xcode

In Xcode, choose New Project... from the File menu (or press SHIFT+CMD+N), then select the Command Line Tool under the macOS Application project type. Click Next and enter a name for the project, for example "firstcups". Click Next and choose a project directory. The click Next to create the project.

In the project window, click on the Build Phases group and expand the Link Binary with Libraries section. Click +, choose "Other...", and then find and choose the `libcups3.dylib` file in `/usr/local/lib`.

Finally, click on the `main.c` file in the sidebar and copy the example program to the file. Build and run (CMD+R) to see the list of destinations.

#### Compiling with GCC

From the command-line, create a file called `simple.c` using your favorite editor, copy the example to this file, and save. Then run the following command to compile it with GCC and run it:

    gcc -o simple `pkg-config --cflags cups3` simple.c `pkg-config --libs cups3`
    ./simple

The `pkg-config` command provides the compiler flags (`pkg-config --cflags cups3`) and libraries (`pkg-config --libs cups3`) needed for the local system.

## Working with Destinations

Destinations, which in CUPS represent individual printers or classes (collections or pools) of printers, are represented by the `cups_dest_t` structure which includes the name ("name"), instance ("instance", saved options/settings), whether the destination is the default for the user ("is_default"), and the options and basic information associated with that destination ("num_options" and "options").

Historically destinations have been manually maintained by the administrator of a system or network, but CUPS also supports dynamic discovery of destinations on the current network.

### Finding Available Destinations

The `cupsEnumDests` function finds all of the available destinations:

    bool
    cupsEnumDests(unsigned flags, int msec, int *cancel,
                  cups_ptype_t type, cups_ptype_t mask,
                  cups_dest_cb_t cb, void *cb_data)

The "flags" argument specifies enumeration options, which at present must be `CUPS_DEST_FLAGS_NONE`.

The "msec" argument specifies the maximum amount of time that should be used for enumeration in milliseconds - interactive applications should keep this value to 5000 or less when run on the main thread.

The "cancel" argument points to an integer variable that, when set to a non-zero value, will cause enumeration to stop as soon as possible. It can be `NULL` if not needed.

The "type" and "mask" arguments are bitfields that allow the caller to filter the destinations based on categories and/or capabilities. The destination's "printer-type" value is masked by the "mask" value and compared to the "type" value when filtering. For example, to only enumerate destinations that are hosted on the local system, pass `CUPS_PTYPE_LOCAL` for the "type" argument and `CUPS_PTYPE_DISCOVERED` for the "mask" argument. The following constants can be used for filtering:

- `CUPS_PTYPE_CLASS`: A collection of destinations.

- `CUPS_PTYPE_FAX`: A facsimile device.

- `CUPS_PTYPE_LOCAL`: A local printer or class. This constant has the value 0 (no bits set) and is only used for the "type" argument and is paired with the `CUPS_PTYPE_REMOTE` or `CUPS_PTYPE_DISCOVERED` constant passed in the "mask" argument.

- `CUPS_PTYPE_REMOTE`: A remote (shared) printer or class.

- `CUPS_PTYPE_DISCOVERED`: An available network printer or class.

- `CUPS_PTYPE_BW`: Can do B&W printing.

- `CUPS_PTYPE_COLOR`: Can do color printing.

- `CUPS_PTYPE_DUPLEX`: Can do two-sided printing.

- `CUPS_PTYPE_STAPLE`: Can staple output.

- `CUPS_PTYPE_COLLATE`: Can quickly collate copies.

- `CUPS_PTYPE_PUNCH`: Can punch output.

- `CUPS_PTYPE_COVER`: Can cover output.

- `CUPS_PTYPE_BIND`: Can bind output.

- `CUPS_PTYPE_FOLD`: Can fold output.

- `CUPS_PTYPE_SORT`: Can sort output (mailboxes, etc.)

- `CUPS_PTYPE_SMALL`: Can print on Letter/Legal/A4-size media.

- `CUPS_PTYPE_MEDIUM`: Can print on Tabloid/B/C/A3/A2-size media.

- `CUPS_PTYPE_LARGE`: Can print on D/E/A1/A0-size media.

- `CUPS_PTYPE_VARIABLE`: Can print on rolls and custom-size media.

The "cb" argument specifies a function to call for every destination that is found:

    typedef bool (*cups_dest_cb_t)(void *cb_data,
                                   unsigned flags,
                                   cups_dest_t *dest);

The callback function receives a copy of the "cb_data" argument along with a bitfield ("flags") and the destination that was found. The "flags" argument can have any of the following constant (bit) values set:

- `CUPS_DEST_FLAGS_MORE`: There are more destinations coming.

- `CUPS_DEST_FLAGS_REMOVED`: The destination has gone away and should be removed from the list of destinations a user can select.

- `CUPS_DEST_FLAGS_ERROR`: An error occurred. The reason for the error can be found by calling the `cupsGetError` and/or `cupsGetErrorString` functions.

The callback function returns `false` to stop enumeration or `true` to continue.

> Note:

> The callback function will likely be called multiple times for the same destination, so it is up to the caller to suppress any duplicate destinations.

The following example shows how to use `cupsEnumDests` to get a filtered array of destinations:

    typedef struct
    {
      size_t num_dests;
      cups_dest_t *dests;
    } my_cb_data_t;

    bool
    my_dest_cb(my_cb_data_t *cb_data, unsigned flags,
               cups_dest_t *dest)
    {
      if (flags & CUPS_DEST_FLAGS_REMOVED)
      {
        // Remove destination from array...
        cb_data->num_dests =
            cupsRemoveDest(dest->name, dest->instance,
                           cb_data->num_dests,
                           &(cb_data->dests));
      }
      else
      {
        // Add destination to array...
        cb_data->num_dests =
            cupsCopyDest(dest, cb_data->num_dests,
                         &(cb_data->dests));
      }

      return (true);
    }

    size_t                     // O - Number of destinations
    my_get_dests(
        cups_ptype_t type,     // I - Printer type bit values
        cups_ptype_t mask,     // I - Printer type mask values
        cups_dest_t  **dests)  // O - Destinations
    {
      my_cb_data_t cb_data = { 0, NULL };

      if (!cupsEnumDests(CUPS_DEST_FLAGS_NONE, 1000, NULL, type,
                         mask, (cups_dest_cb_t)my_dest_cb,
                         &cb_data))
      {
        // An error occurred, free all of the destinations and
        // return...
        cupsFreeDests(cb_data.num_dests, cb_data.dests);

        *dests = NULL;

        return (0);
      }

      // Return the destination array...
      *dests = cb_data.dests;

      return (cb_data.num_dests);
    }

### Basic Destination Information

The "num_options" and "options" members of the `cups_dest_t` structure provide basic attributes about the destination in addition to the user default options and values for that destination. The following names are predefined for various destination attributes:

- "printer-info": The human-readable description of the destination such as "My Laser Printer".

- "printer-is-accepting-jobs": "true" if the destination is accepting new jobs, "false" otherwise.

- "printer-is-shared": "true" if the destination is being shared with other computers, "false" otherwise.

- "printer-location": The human-readable location of the destination such as "Lab 4".

- "printer-make-and-model": The human-readable make and model of the destination such as "ExampleCorp LaserPrinter 4000 Series".

- "printer-state": "3" if the destination is idle, "4" if the destination is printing a job, and "5" if the destination is stopped.

- "printer-state-change-time": The UNIX time when the destination entered the current state.

- "printer-state-reasons": Additional comma-delimited state keywords for the destination such as "media-tray-empty-error" and "toner-low-warning".

- "printer-type": The `cups_ptype_t` value associated with the destination.

- "printer-uri-supported": The URI associated with the destination; if not set, this destination was discovered but is not yet setup as a local printer.

Use the `cupsGetOption` function to retrieve the value. For example, the following code gets the make and model of a destination:

    const char *model = cupsGetOption("printer-make-and-model",
                                      dest->num_options,
                                      dest->options);

### Detailed Destination Information

Once a destination has been chosen, the `cupsCopyDestInfo` function can be used to gather detailed information about the destination:

    cups_dinfo_t *
    cupsCopyDestInfo(http_t *http, cups_dest_t *dest, cups_dest_flags_t dflags);

The "http" argument specifies a connection to the CUPS scheduler and is typically the constant `CUPS_HTTP_DEFAULT`. The "dest" argument specifies the destination to query. The "dflags" argument specifies whether to get the information from the local spooler (`CUPS_DEST_FLAGS_NONE`) or from the printer (`CUPS_DEST_FLAGS_DEVICE`).

The `cups_dinfo_t` structure that is returned contains a snapshot of the supported options and their supported, ready, and default values. It also can report constraints between different options and values, and recommend changes to resolve those constraints.

#### Getting Supported Options and Values

The `cupsCheckDestSupported` function can be used to test whether a particular option or option and value is supported:

    bool
    cupsCheckDestSupported(http_t *http, cups_dest_t *dest,
                           cups_dinfo_t *info,
                           const char *option,
                           const char *value);

The "option" argument specifies the name of the option to check. The following constants can be used to check the various standard options:

- `CUPS_COPIES`: Controls the number of copies that are produced.

- `CUPS_FINISHINGS`: A comma-delimited list of integer constants that control the finishing processes that are applied to the job, including stapling, punching, and folding.

- `CUPS_MEDIA`: Controls the media size that is used, typically one of the following: `CUPS_MEDIA_3X5`, `CUPS_MEDIA_4X6`, `CUPS_MEDIA_5X7`, `CUPS_MEDIA_8X10`, `CUPS_MEDIA_A3`, `CUPS_MEDIA_A4`, `CUPS_MEDIA_A5`, `CUPS_MEDIA_A6`, `CUPS_MEDIA_ENV10`, `CUPS_MEDIA_ENVDL`, `CUPS_MEDIA_LEGAL`, `CUPS_MEDIA_LETTER`, `CUPS_MEDIA_PHOTO_L`, `CUPS_MEDIA_SUPERBA3`, or `CUPS_MEDIA_TABLOID`.

- `CUPS_MEDIA_SOURCE`: Controls where the media is pulled from, typically either `CUPS_MEDIA_SOURCE_AUTO` or `CUPS_MEDIA_SOURCE_MANUAL`.

- `CUPS_MEDIA_TYPE`: Controls the type of media that is used, typically one of the following: `CUPS_MEDIA_TYPE_AUTO`, `CUPS_MEDIA_TYPE_ENVELOPE`, `CUPS_MEDIA_TYPE_LABELS`, `CUPS_MEDIA_TYPE_LETTERHEAD`, `CUPS_MEDIA_TYPE_PHOTO`, `CUPS_MEDIA_TYPE_PHOTO_GLOSSY`, `CUPS_MEDIA_TYPE_PHOTO_MATTE`, `CUPS_MEDIA_TYPE_PLAIN`, or `CUPS_MEDIA_TYPE_TRANSPARENCY`.

- `CUPS_NUMBER_UP`: Controls the number of document pages that are placed on each media side.

- `CUPS_ORIENTATION`: Controls the orientation of document pages placed on the media: `CUPS_ORIENTATION_PORTRAIT` or `CUPS_ORIENTATION_LANDSCAPE`.

- `CUPS_PRINT_COLOR_MODE`: Controls whether the output is in color (`CUPS_PRINT_COLOR_MODE_COLOR`), grayscale (`CUPS_PRINT_COLOR_MODE_MONOCHROME`), or either (`CUPS_PRINT_COLOR_MODE_AUTO`).

- `CUPS_PRINT_QUALITY`: Controls the generate quality of the output: `CUPS_PRINT_QUALITY_DRAFT`, `CUPS_PRINT_QUALITY_NORMAL`, or `CUPS_PRINT_QUALITY_HIGH`.

- `CUPS_SIDES`: Controls whether prints are placed on one or both sides of the media: `CUPS_SIDES_ONE_SIDED`, `CUPS_SIDES_TWO_SIDED_PORTRAIT`, or `CUPS_SIDES_TWO_SIDED_LANDSCAPE`.

If the "value" argument is `NULL`, the `cupsCheckDestSupported` function returns whether the option is supported by the destination. Otherwise, the function returns whether the specified value of the option is supported.

The `cupsFindDestSupported` function returns the IPP attribute containing the supported values for a given option:

    ipp_attribute_t *
    cupsFindDestSupported(http_t *http, cups_dest_t *dest,
                          cups_dinfo_t *dinfo,
                          const char *option);

For example, the following code prints the supported finishing processes for a destination, if any, to the standard output:

    cups_dinfo_t *info = cupsCopyDestInfo(CUPS_HTTP_DEFAULT, dest,
                                          CUPS_DEST_FLAGS_NONE);

    if (cupsCheckDestSupported(CUPS_HTTP_DEFAULT, dest, info,
                               CUPS_FINISHINGS, NULL))
    {
      ipp_attribute_t *finishings =
          cupsFindDestSupported(CUPS_HTTP_DEFAULT, dest, info,
                                CUPS_FINISHINGS);
      size_t i, count = ippGetCount(finishings);

      puts("finishings supported:");
      for (i = 0; i < count; i ++)
        printf("  %d (%s)\n", ippGetInteger(finishings, i),
               ippEnumString("finishings", ippGetInteger(finishings, i)));
    }
    else
      puts("finishings not supported.");

The "job-creation-attributes" option can be queried to get a list of supported options. For example, the following code prints the list of supported options to the standard output:

    ipp_attribute_t *attrs =
        cupsFindDestSupported(CUPS_HTTP_DEFAULT, dest, info,
                              "job-creation-attributes");
    size_t i, count = ippGetCount(attrs);

    for (i = 0; i < count; i ++)
      puts(ippGetString(attrs, i, NULL));

#### Getting Default Values

There are two sets of default values - user defaults that are available via the "num_options" and "options" members of the `cups_dest_t` structure, and destination defaults that available via the `cups_dinfo_t` structure and the `cupsFindDestDefault` function which returns the IPP attribute containing the default value(s) for a given option:

    ipp_attribute_t *
    cupsFindDestDefault(http_t *http, cups_dest_t *dest,
                        cups_dinfo_t *dinfo,
                        const char *option);

The user defaults from `cupsGetOption` should always take preference over the destination defaults. For example, the following code prints the default finishings value(s) to the standard output:

    const char *def_value =
        cupsGetOption(CUPS_FINISHINGS, dest->num_options,
                      dest->options);
    ipp_attribute_t *def_attr =
        cupsFindDestDefault(CUPS_HTTP_DEFAULT, dest, info,
                            CUPS_FINISHINGS);

    if (def_value != NULL)
    {
      printf("Default finishings: %s\n", def_value);
    }
    else
    {
      int i, count = ippGetCount(def_attr);

      printf("Default finishings: %d",
             ippGetInteger(def_attr, 0));
      for (i = 1; i < count; i ++)
        printf(",%d", ippGetInteger(def_attr, i));
      putchar('\n');
    }

#### Getting Ready (Loaded) Values

The finishings and media options also support queries for the ready, or loaded, values. For example, a printer may have punch and staple finishers installed but be out of staples - the supported values will list both punch and staple finishing processes but the ready values will only list the punch processes. Similarly, a printer may support hundreds of different sizes of media but only have a single size loaded at any given time - the ready values are limited to the media that is actually in the printer.

The `cupsFindDestReady` function finds the IPP attribute containing the ready values for a given option:

    ipp_attribute_t *
    cupsFindDestReady(http_t *http, cups_dest_t *dest,
                      cups_dinfo_t *dinfo, const char *option);

For example, the following code lists the ready finishing processes:

    ipp_attribute_t *ready_finishings =
        cupsFindDestReady(CUPS_HTTP_DEFAULT, dest, info,
                          CUPS_FINISHINGS);

    if (ready_finishings != NULL)
    {
      int i, count = ippGetCount(ready_finishings);

      puts("finishings ready:");
      for (i = 0; i < count; i ++)
        printf("  %d\n", ippGetInteger(ready_finishings, i));
    }
    else
      puts("no finishings are ready.");

#### Media Options

CUPS provides functions for querying the dimensions, margins, color, source (tray/roll), and type for each of the supported media size options. The `cups_media_t` structure is used to describe media:

    typedef struct cups_media_s
    {
      char media[128];
      char color[128];
      char source[128];
      char type[128];
      int width, length;
      int bottom, left, right, top;
    } cups_media_t;

The "media" member specifies a PWG self-describing media size name such as "na_letter_8.5x11in", "iso_a4_210x297mm", etc. The "color" member specifies a PWG media color name such as "white", "blue", etc. The "source" member specifies a standard keyword for the paper tray or roll such as "tray-1", "manual", "by-pass-tray" (multi-purpose tray), etc. The "type" member specifies a PWG media type name such as "stationery" (plain paper), "photographic", "envelope", "transparency", etc.

The "width" and "length" members specify the dimensions of the media in hundredths of millimeters (1/2540th of an inch). The "bottom", "left", "right", and "top" members specify the margins of the printable area, also in hundredths of millimeters.

The `cupsGetDestMediaByName` and `cupsGetDestMediaBySize` functions lookup the media information using a standard media size name or dimensions in hundredths of millimeters:

    bool
    cupsGetDestMediaByName(http_t *http, cups_dest_t *dest,
                           cups_dinfo_t *dinfo,
                           const char *media,
                           unsigned flags, cups_media_t *size);

    bool
    cupsGetDestMediaBySize(http_t *http, cups_dest_t *dest,
                           cups_dinfo_t *dinfo,
                           int width, int length,
                           unsigned flags, cups_media_t *size);

The "media", "width", and "length" arguments specify the size to lookup. The "flags" argument specifies a bitfield controlling various lookup options:

- `CUPS_MEDIA_FLAGS_DEFAULT`: Find the closest size supported by the printer.

- `CUPS_MEDIA_FLAGS_BORDERLESS`: Find a borderless size.

- `CUPS_MEDIA_FLAGS_DUPLEX`: Find a size compatible with two-sided printing.

- `CUPS_MEDIA_FLAGS_EXACT`: Find an exact match for the size.

- `CUPS_MEDIA_FLAGS_READY`: If the printer supports media sensing or configuration of the media in each tray/source, find the size amongst the "ready" media.

If a matching size is found for the destination, the size information is stored in the structure pointed to by the "size" argument and `true` is returned. Otherwise `false` is returned.

For example, the following code prints the margins for two-sided printing on US Letter media:

    cups_media_t size;

    if (cupsGetDestMediaByName(CUPS_HTTP_DEFAULT, dest, info,
                               CUPS_MEDIA_LETTER,
                               CUPS_MEDIA_FLAGS_DUPLEX, &size))
    {
      puts("Margins for duplex US Letter:");
      printf("  Bottom: %.2fin\n", size.bottom / 2540.0);
      printf("    Left: %.2fin\n", size.left / 2540.0);
      printf("   Right: %.2fin\n", size.right / 2540.0);
      printf("     Top: %.2fin\n", size.top / 2540.0);
    }
    else
      puts("Margins for duplex US Letter are not available.");

You can also enumerate all of the sizes that match a given "flags" value using the `cupsGetDestMediaByIndex` and `cupsGetDestMediaCount` functions:

    bool
    cupsGetDestMediaByIndex(http_t *http, cups_dest_t *dest,
                            cups_dinfo_t *dinfo, size_t n,
                            unsigned flags, cups_media_t *size);

    size_t
    cupsGetDestMediaCount(http_t *http, cups_dest_t *dest,
                          cups_dinfo_t *dinfo, unsigned flags);

For example, the following code prints the list of ready media and corresponding margins:

    cups_media_t media;
    size_t i;
    size_t count = cupsGetDestMediaCount(CUPS_HTTP_DEFAULT,
                                         dest, info,
                                         CUPS_MEDIA_FLAGS_READY);

    for (i = 0; i < count; i ++)
    {
      if (cupsGetDestMediaByIndex(CUPS_HTTP_DEFAULT, dest, info,
                                  i, CUPS_MEDIA_FLAGS_READY,
                                  &size))
      {
        printf("%s:\n", media.name);
        printf("    Width: %.2fin\n", media.width / 2540.0);
        printf("   Length: %.2fin\n", media.length / 2540.0);
        printf("   Bottom: %.2fin\n", media.bottom / 2540.0);
        printf("     Left: %.2fin\n", media.left / 2540.0);
        printf("    Right: %.2fin\n", media.right / 2540.0);
        printf("      Top: %.2fin\n", media.top / 2540.0);
        printf("Tray/Roll: %s\n", media.source);
        printf("    Color: %s\n", media.color);
        printf("     Type: %s\n", media.type);
      }
    }

Finally, the `cupsGetDestMediaDefault` function returns the default media size:

    bool
    cupsGetDestMediaDefault(http_t *http, cups_dest_t *dest,
                            cups_dinfo_t *dinfo, unsigned flags,
                            cups_media_t *size);

#### Localizing Options and Values

CUPS provides three functions to get localized, human-readable strings in the user's current locale for options and values: `cupsLocalizeDestMedia`, `cupsLocalizeDestOption`, and `cupsLocalizeDestValue`:

    const char *
    cupsLocalizeDestMedia(http_t *http, cups_dest_t *dest,
                          cups_dinfo_t *info, unsigned flags,
                          cups_media_t *media);

    const char *
    cupsLocalizeDestOption(http_t *http, cups_dest_t *dest,
                           cups_dinfo_t *info,
                           const char *option);

    const char *
    cupsLocalizeDestValue(http_t *http, cups_dest_t *dest,
                          cups_dinfo_t *info,
                          const char *option, const char *value);

> Note:

> These functions require a valid `http_t` connection to work. Use the `cupsConnectDest` function to connect to the destination for its localization information.

For example, the following code will list the localized media names for a destination:

    char resource[256];
    http_t *http = cupsConnectDest(dest, CUPS_DEST_FLAGS_NONE,
                                   /*msec*/30000, /*cancel*/NULL,
                                   resource, sizeof(resource),
                                   /*dest_cb*/NULL, /*user_data*/NULL);

    size_t i;
    size_t count = cupsGetDestMediaCount(http, dest, info,
                                         CUPS_MEDIA_FLAGS_DEFAULT);
    cups_media_t media;
    for (i = 0; i < count; i ++)
    {
      if (cupsGetDestMediaByIndex(http, dest, info, i,
                                  CUPS_MEDIA_FLAGS_DEFAULT, &media))
        printf("%s: %s\n", media.name,
               cupsLocalizeDestMedia(http, dest, info,
                                     CUPS_MEDIA_FLAGS_DEFAULT, &media));
    }

### Submitting a Print Job

Once you are ready to submit a print job, you create a job using the `cupsCreateDestJob` function:

    ipp_status_t
    cupsCreateDestJob(http_t *http, cups_dest_t *dest,
                      cups_dinfo_t *info, int *job_id,
                      const char *title, int num_options,
                      cups_option_t *options);

The "title" argument specifies a name for the print job such as "My Document". The "num_options" and "options" arguments specify the options for the print job which are allocated using the `cupsAddOption` function.

When successful, the job's numeric identifier is stored in the integer pointed to by the "job_id" argument and `IPP_STATUS_OK` is returned. Otherwise, an IPP error status is returned.

For example, the following code creates a new job that will print 42 copies of a two-sided US Letter document:

    int job_id = 0;
    size_ num_options = 0;
    cups_option_t *options = NULL;

    num_options = cupsAddIntegerOption(CUPS_COPIES, 42,
                                       num_options, &options);
    num_options = cupsAddOption(CUPS_MEDIA, CUPS_MEDIA_LETTER,
                                num_options, &options);
    num_options = cupsAddOption(CUPS_SIDES,
                                CUPS_SIDES_TWO_SIDED_PORTRAIT,
                                num_options, &options);

    if (cupsCreateDestJob(CUPS_HTTP_DEFAULT, dest, info,
                          &job_id, "My Document", num_options,
                          options) == IPP_STATUS_OK)
      printf("Created job: %d\n", job_id);
    else
      printf("Unable to create job: %s\n",
             cupsGetErrorString());

Once the job is created, you submit documents for the job using the `cupsStartDestDocument`, `cupsWriteRequestData`, and `cupsFinishDestDocument` functions:

    http_status_t
    cupsStartDestDocument(http_t *http, cups_dest_t *dest,
                          cups_dinfo_t *info, int job_id,
                          const char *docname,
                          const char *format,
                          size_t num_options,
                          cups_option_t *options,
                          bool last_document);

    http_status_t
    cupsWriteRequestData(http_t *http, const char *buffer,
                         size_t length);

    ipp_status_t
    cupsFinishDestDocument(http_t *http, cups_dest_t *dest,
                           cups_dinfo_t *info);

The "docname" argument specifies the name of the document, typically the original filename. The "format" argument specifies the MIME media type of the document, including the following constants:

- `CUPS_FORMAT_AUTO`: "application/octet-stream"

- `CUPS_FORMAT_JPEG`: "image/jpeg"

- `CUPS_FORMAT_PDF`: "application/pdf"

- `CUPS_FORMAT_TEXT`: "text/plain"

The "num_options" and "options" arguments specify per-document print options, which at present must be `0` and `NULL`. The "last_document" argument specifies whether this is the last document in the job.

For example, the following code submits a PDF file to the job that was just created:

    FILE *fp = fopen("filename.pdf", "rb");
    size_t bytes;
    char buffer[65536];

    if (cupsStartDestDocument(CUPS_HTTP_DEFAULT, dest, info,
                              job_id, "filename.pdf", 0, NULL,
                              1) == HTTP_STATUS_CONTINUE)
    {
      while ((bytes = fread(buffer, 1, sizeof(buffer), fp)) > 0)
      {
        if (cupsWriteRequestData(CUPS_HTTP_DEFAULT, buffer,
                                 bytes) != HTTP_STATUS_CONTINUE)
          break;
      }

      if (cupsFinishDestDocument(CUPS_HTTP_DEFAULT, dest,
                                 info) == IPP_STATUS_OK)
        puts("Document send succeeded.");
      else
        printf("Document send failed: %s\n",
               cupsGetErrorString());
    }

    fclose(fp);

## Sending IPP Requests

CUPS provides a rich API for sending IPP requests to the scheduler or printers, typically from management or utility applications whose primary purpose is not to send print jobs.

### Connecting to the Scheduler or Printer

The connection to the scheduler or printer is represented by the HTTP connection type `http_t`. The `cupsConnectDest` function connects to the scheduler or printer associated with the destination:

    http_t *
    cupsConnectDest(cups_dest_t *dest, unsigned flags, int msec,
                    int *cancel, char *resource,
                    size_t resourcesize, cups_dest_cb_t cb,
                    void *cb_data);

The "dest" argument specifies the destination to connect to.

The "flags" argument specifies whether you want to connect to the scheduler (`CUPS_DEST_FLAGS_NONE`) or device/printer (`CUPS_DEST_FLAGS_DEVICE`) associated with the destination.

The "msec" argument specifies how long you are willing to wait for the connection to be established in milliseconds. Specify a value of `-1` to wait indefinitely.

The "cancel" argument specifies the address of an integer variable that can be set to a non-zero value to cancel the connection. Specify a value of `NULL` to not provide a cancel variable.

The "resource" and "resourcesize" arguments specify the address and size of a character string array to hold the path to use when sending an IPP request.

The "cb" and "cb_data" arguments specify a destination callback function that returns `true` to continue connecting or `false` to stop. The destination callback works the same way as the one used for the `cupsEnumDests` function.

On success, a HTTP connection is returned that can be used to send IPP requests and get IPP responses.

For example, the following code connects to the printer associated with a destination with a 30 second timeout:

    char resource[256];
    http_t *http = cupsConnectDest(dest, CUPS_DEST_FLAGS_DEVICE,
                                   30000, /*cancel*/NULL, resource,
                                   sizeof(resource),
                                   /*cb*/NULL, /*cb_data*/NULL);

### Creating an IPP Request

IPP requests are represented by the IPP message type `ipp_t` and each IPP attribute in the request is representing using the type `ipp_attribute_t`. Each IPP request includes an operation code (`IPP_OP_CREATE_JOB`, `IPP_OP_GET_PRINTER_ATTRIBUTES`, etc.) and a 32-bit integer identifier.

The `ippNewRequest` function creates a new IPP request with a process-unique identifier:

    ipp_t *
    ippNewRequest(ipp_op_t op);

The "op" argument specifies the IPP operation code for the request. For example, the following code creates an IPP Get-Printer-Attributes request:

    ipp_t *request = ippNewRequest(IPP_OP_GET_PRINTER_ATTRIBUTES);

The request identifier is automatically set to a unique value for the current process.

Each IPP request starts with two IPP attributes, "attributes-charset" and "attributes-natural-language", followed by IPP attribute(s) that specify the target of the operation. The `ippNewRequest` function automatically adds the correct "attributes-charset" and "attributes-natural-language" attributes, but you must add the target attribute(s). For example, the following code adds the "printer-uri" attribute to the IPP Get-Printer-Attributes request to specify which printer is being queried:

    const char *printer_uri = cupsGetOption("device-uri",
                                            dest->num_options,
                                            dest->options);

    ippAddString(request, IPP_TAG_OPERATION, IPP_TAG_URI,
                 "printer-uri", /*language*/NULL, printer_uri);

> Note:

> If we wanted to query the scheduler instead of the device, we would look up the "printer-uri-supported" option instead of the "device-uri" option.

The `ippAddString` function adds the "printer-uri" attribute the the IPP request. The `IPP_TAG_OPERATION` argument specifies that the attribute is part of the operation attributes group. The `IPP_TAG_URI` argument specifies that the value is a Universal Resource Identifier (URI) string. The `NULL` argument specifies there is no language (English, French, Japanese, etc.) associated with the string, and the "printer_uri" argument specifies the string value.

The IPP Get-Printer-Attributes request also supports an IPP attribute called "requested-attributes" that lists the attributes and values you are interested in. For example, the following code requests the printer state attributes:

    static const char * const requested_attributes[] =
    {
      "printer-state",
      "printer-state-message",
      "printer-state-reasons"
    };

    ippAddStrings(request, IPP_TAG_OPERATION, IPP_TAG_KEYWORD,
                  "requested-attributes", /*num_values*/3, /*language*/NULL,
                  requested_attributes);

The `ippAddStrings` function adds an attribute with one or more strings, in this case three. The `IPP_TAG_KEYWORD` argument specifies that the strings are keyword values, which are used for attribute names. All strings use the same language (`NULL`), and the attribute will contain the three strings from the array `requested_attributes`.

CUPS provides many functions to adding attributes of different types:

- `ippAddBoolean` adds a boolean (`IPP_TAG_BOOLEAN`) attribute with one value.

- `ippAddCollection` adds a collection (`IPP_TAG_BEGIN_COLLECTION`) attribute with one value.

- `ippAddCollections` adds a collection (`IPP_TAG_BEGIN_COLLECTION`) attribute with one or more values.

- `ippAddInteger` adds an enum (`IPP_TAG_ENUM`) or integer (`IPP_TAG_INTEGER`) attribute with one value.

- `ippAddIntegers` adds an enum or integer attribute with one or more values.

- `ippAddOctetString` adds an octetString attribute with one value.

- `ippAddOutOfBand` adds a admin-defined (`IPP_TAG_ADMINDEFINE`), default (`IPP_TAG_DEFAULT`), delete-attribute (`IPP_TAG_DELETEATTR`), no-value (`IPP_TAG_NOVALUE`), not-settable (`IPP_TAG_NOTSETTABLE`), unknown (`IPP_TAG_UNKNOWN`), or unsupported (`IPP_TAG_UNSUPPORTED_VALUE`) out-of-band attribute.

- `ippAddRange` adds a rangeOfInteger attribute with one range.

- `ippAddRanges` adds a rangeOfInteger attribute with one or more ranges.

- `ippAddResolution` adds a resolution attribute with one resolution.

- `ippAddResolutions` adds a resolution attribute with one or more resolutions.

- `ippAddString` adds a charset (`IPP_TAG_CHARSET`), keyword (`IPP_TAG_KEYWORD`), mimeMediaType (`IPP_TAG_MIMETYPE`), name (`IPP_TAG_NAME` and `IPP_TAG_NAMELANG`), naturalLanguage (`IPP_TAG_NATURAL_LANGUAGE`), text (`IPP_TAG_TEXT` and `IPP_TAG_TEXTLANG`), uri (`IPP_TAG_URI`), or uriScheme (`IPP_TAG_URISCHEME`) attribute with one value.

- `ippAddStrings` adds a charset, keyword, mimeMediaType, name, naturalLanguage, text, uri, or uriScheme attribute with one or more values.

### Sending the IPP Request

Once you have created the IPP request, you can send it using the `cupsDoRequest` function. For example, the following code sends the IPP Get-Printer-Attributes request to the destination and saves the response:

    ipp_t *response = cupsDoRequest(http, request, resource);

For requests like Send-Document that include a file, the `cupsDoFileRequest` function should be used:

    ipp_t *response = cupsDoFileRequest(http, request, resource,
                                        filename);

Both `cupsDoRequest` and `cupsDoFileRequest` free the IPP request. If a valid IPP response is received, it is stored in a new IPP message (`ipp_t`) and returned to the caller. Otherwise `NULL` is returned.

The status from the most recent request can be queried using the `cupsGetError` function, for example:

    if (cupsGetError() >= IPP_STATUS_ERROR_BAD_REQUEST)
    {
      /* request failed */
    }

A human-readable error message is also available using the `cupsGetErrorString` function:

    if (cupsGetError() >= IPP_STATUS_ERROR_BAD_REQUEST)
    {
      /* request failed */
      printf("Request failed: %s\n", cupsGetErrorString());
    }

### Processing the IPP Response

Each response to an IPP request is also an IPP message (`ipp_t`) with its own IPP attributes (`ipp_attribute_t`) that includes a status code (`IPP_STATUS_OK`, `IPP_STATUS_ERROR_BAD_REQUEST`, etc.) and the corresponding 32-bit integer identifier from the request.

CUPS provides many functions to access the attributes and values in an IPP response message:

- `ippFindAttribute` finds the first occurrence of an attribute.

- `ippFindNextAttribute` finds the next occurrence of an attribute.

- `ippGetBoolean` gets a boolean value for an attribute.

- `ippGetCollection` gets a collection value for an attribute.

- `ippGetCount` gets the number of values in an attribute.

- `ippGetDate` gets a date value for an attribute.

- `ippGetFirstAttribute` gets the first attribute in the IPP response.

- `ippGetGroupTag` gets the group tag associated with an attribute.

- `ippGetInteger` gets the integer or enum value for an attribute.

- `ippGetName` gets the name of an attribute.

- `ippGetNextAttribute` gets the next attribute in the IPP response.

- `ippGetOctetString` gets an octetString value for an attribute.

- `ippGetRange` gets a rangeOfInteger value for an attribute.

- `ippGetRequestId` gets the request ID number for the IPP response.

- `ippGetResolution` gets a resolution value for an attribute.

- `ippGetStatusCode` gets the status code for the IPP response.

- `ippGetString` gets a string value for an attribute.

- `ippGetValueTag` gets the value tag ("syntax") for an attribute.

- `ippGetVersion` gets the IPP version used for the IPP response.

- `ippRestore` restores a previous position in the IPP response.

- `ippSave` saves the current position in the IPP response.

For example, the following code finds the printer state attributes and prints their values:

    ipp_attribute_t *attr;

    if ((attr = ippFindAttribute(response, "printer-state",
                                 IPP_TAG_ENUM)) != NULL)
    {
      printf("printer-state=%s\n",
             ippEnumString("printer-state", ippGetInteger(attr, 0)));
    }
    else
    {
      puts("printer-state=unknown");
    }

    if ((attr = ippFindAttribute(response, "printer-state-message",
                                 IPP_TAG_TEXT)) != NULL)
    {
      printf("printer-state-message=\"%s\"\n",
             ippGetString(attr, 0, NULL)));
    }

    if ((attr = ippFindAttribute(response, "printer-state-reasons",
                                 IPP_TAG_KEYWORD)) != NULL)
    {
      size_t i, count = ippGetCount(attr);

      puts("printer-state-reasons=");
      for (i = 0; i < count; i ++)
        printf("    %s\n", ippGetString(attr, i, NULL)));
    }

Once you are done using the IPP response message, free it using the `ippDelete` function:

    ippDelete(response);

## Authentication and Authorization

CUPS supports authentication and authorization using HTTP Basic, HTTP Digest, peer credentials when communicating over domain sockets, and OAuth/OpenID Connect.

Peer credential authorization happens automatically when connected over a domain socket. Other types of authentication requires the application to handle `HTTP_STATUS_UNAUTHORIZED` responses beyond simply calling `cupsDoAuthentication`.

### Authentication Using Passwords

When you call `cupsDoAuthentication` and the HTTP server requires the "Basic" or "Digest" authentication schemes, CUPS normally requests a password from the console. GUI applications should set a password callback using the `cupsSetPasswordCB` function:

    void
    cupsSetPasswordCB(cups_password_cb_t cb, void *cb_data);

The password callback is called when needed and is responsible for setting the current user name using `cupsSetUser` and returning a (password) string:

    const char *
    cups_password_cb(const char *prompt, http_t *http,
                     const char *method, const char *resource,
                     void *cb_data);

The "prompt" argument is a string from CUPS that should be displayed to the user.

The "http" argument is the connection hosting the request that is being authenticated. The password callback can call the `httpGetField` and `httpGetSubField` functions to look for additional details concerning the authentication challenge.

The "method" argument specifies the HTTP method used for the request and is typically "GET", "POST", or "PUT".

The "resource" argument specifies the path or URI used for the request.

The "cb_data" argument provides the data pointer from the `cupsSetPasswordCB` call.

### Authorization using OAuth/OpenID Connect

When you call `cupsDoAuthentication` and the HTTP server requires the "Bearer" authentication scheme, CUPS will call an OAuth callback that you register using the `cupsSetOAuthCB` function:

    void
    cupsSetOAuthCB(cups_oauth_cb_t cb, void *cb_data);

The OAuth callback is called when needed and is responsible for performing any necessary authorization and returning an access token string:

    const char *
    cups_oauth_cb(http_t *http, const char *realm, const char *scope,
                  const char *resource, void *cb_data);

The "http" argument is the connection hosting the request that is being authenticated. The OAuth callback can call the `httpGetField` and `httpGetSubField` functions to look for additional details concerning the authentication challenge.

The "realm" and "scope" arguments provide the "realm" and "scope" parameters, if any, from the "WWW-Authenticate" header.

The "resource" argument specifies the path or URI used for the request.

The "cb_data" argument provides the data pointer from the `cupsSetOAuthCB` call.

#### OAuth Client Functions

CUPS provides a generic OAuth/OpenID client for authorizing access to printers and other network resources. The following functions are provided:

- `cupsOAuthClearTokens`: Clear all cached tokens.

- `cupsOAuthCopyAccessToken`: Copy the cached access token.

- `cupsOAuthCopyClientId`: Copy the cached client ID.

- `cupsOAuthCopyRefreshToken`: Copy the cached refresh token.

- `cupsOAuthCopyUserId`: Copy the cached user ID.

- `cupsOAuthGetAuthorizationCode`: Get an authorization code using a web browser.

- `cupsOAuthGetClientId`: Get a client ID using dynamic client registration.

- `cupsOAuthGetDeviceGrant`: Get a device authorization grant code.

- `cupsOAuthGetJWKS`: Get the key set for an authorization server.

- `cupsOAuthGetMetadata`: Get the metadata for an authorization server.

- `cupsOAuthGetTokens`: Get access and refresh tokens for an authorization/grant code.

- `cupsOAuthGetUserId`: Get the user ID associated with an access token.

- `cupsOAuthMakeAuthorizationURL`: Make the URL for web browser authorization.

- `cupsOAuthMakeBase64Random`: Make a Base64-encoded string of random bytes.

- `cupsOAuthSaveClientData`: Save a client ID and secret for an authorization server.

- `cupsOAuthSaveTokens`: Save access and refresh tokens for an authorization server.

Once you have an access token you use the `httpSetAuthString` function to use it for a HTTP connection:

    http_t *http;
    char   *access_token;

    httpSetAuthString(http, "Bearer", access_token);

#### Authorizing Using a Web Browser

Users can authorize using their preferred web browser via the `cupsOAuthGetAuthorizationCode` function, which returns an authorization grant code string. The following code gets the authorization server metadata, authorizes access through the web browser, and then obtains a HTTP Bearer access token:

    http_t      *http;           // HTTP connection
    const char  *auth_uri;       // Base URL for Authorization Server
    cups_json_t *metadata;       // Authorization Server metadata
    const char  *printer_uri;    // Printer URI
    char        *auth_code;      // Authorization grant code
    char        *access_token;   // Access token
    time_t      access_expires;  // Date/time when access token expires

    // Get the metadata for the authorization server.
    metadata = cupsOAuthGetMetadata(auth_uri);

    if (metadata == NULL)
    {
      // Handle error getting metadata from authorization server.
    }

    // Bring up the web browser to authorize and get an authorization code.
    auth_code = cupsOAuthGetAuthorizationCode(auth_uri, metadata, printer_uri,
                                              /*scopes*/NULL,
                                              /*redirect_uri*/NULL);

    if (auth_code == NULL)
    {
      // Unable to authorize.
    }

    // Get the access code from the authorization code.
    access_token = cupsOAuthGetTokens(auth_uri, metadata, printer_uri, auth_code,
                                      CUPS_OGRANT_AUTHORIZATION_CODE,
                                      /*redirect_uri*/NULL, &access_expires);

    if (access_token == NULL)
    {
      // Unable to get access token.
    }

    // Set the Bearer token for authorization.
    httpSetAuthString(http, "Bearer", access_token);
    free(access_token);

#### Authorizing Using a Mobile Device

Users can authorize using a mobile device via the `cupsOAuthGetDeviceGrant` function, which returns a JSON object with the mobile authorization URLs, user (verification) code string, and device grant code. The following code gets the authorization server metadata, gets the mobile device authorization information, and then obtains a HTTP Bearer access token:

    http_t      *http;           // HTTP connection
    const char  *auth_uri;       // Base URL for Authorization Server
    cups_json_t *metadata;       // Authorization Server metadata
    const char  *printer_uri;    // Printer URI
    cups_json_t *device_grant;   // Device authorization grant object
    const char  *device_code;    // Device grant code
    const char  *verify_url;     // Mobile device URL
    const char  *verify_urlc;    // Mobile device URL with user code
    const char  *user_code;      // User code
    char        *access_token;   // Access token
    time_t      access_expires;  // Date/time when access token expires

    // Get the metadata for the authorization server.
    metadata = cupsOAuthGetMetadata(auth_uri);

    if (metadata == NULL)
    {
      // Handle error getting metadata from authorization server.
    }

    // Get a device authorization grant for mobile authorization.
    device_grant = cupsOAuthGetDeviceGrant(auth_uri, metadata, printer_uri,
                                           /*scopes*/NULL);

    device_code = cupsJSONGetString(
                      cupsJSONFind(device_grant, CUPS_ODEVGRANT_DEVICE_CODE));
    verify_url  = cupsJSONGetString(
                      cupsJSONFind(device_grant, CUPS_ODEVGRANT_VERIFICATION_URI));
    verify_urlc = cupsJSONGetString(
                      cupsJSONFind(device_grant, CUPS_ODEVGRANT_VERIFICATION_URI_COMPLETE));
    user_code   = cupsJSONGetString(
                      cupsJSONFind(device_grant, CUPS_ODEVGRANT_USER_CODE));

    if (device_code == NULL || verify_url == NULL || verify_urlc == NULL ||
        user_code == NULL)
    {
      // Unable to authorize.
    }

    // Show the URLs and user code to the user (links and/or QR codes).
    printf("Open this URL: %s\n", verify_urlc);

    // Get the access code from the authorization code.
    do
    {
      // Delay check for several seconds.
      sleep(5);

      // Try getting an access token.
      access_token = cupsOAuthGetTokens(auth_uri, metadata, printer_uri, device_code,
                                        CUPS_OGRANT_DEVICE_CODE,
                                        /*redirect_uri*/NULL, &access_expires);
    }
    while (access_token == NULL && access_expires > 0);
           // Continue checking until we have an access token or
           // the device code has expired.

    if (access_token == NULL)
    {
      // Unable to get access token.
    }

    // Set the Bearer token for authorization.
    httpSetAuthString(http, "Bearer", access_token);
    free(access_token);

#### Supported OAuth Standards

The following standards are supported:

- OpenID Connect Core v1.0

- RFC 6749: The OAuth 2.0 Authorization Framework

- RFC 6750: The OAuth 2.0 Authorization Framework: Bearer Token Usage

- RFC 7591: OAuth 2.0 Dynamic Client Registration Protocol

- RFC 7636: Proof Key for Code Exchange by OAuth Public Clients

- RFC 8252: OAuth 2.0 for Native Apps

- RFC 8414: OAuth 2.0 Authorization Server Metadata

- RFC 8628: OAuth 2.0 Device Authorization Grant

- RFC 8693: OAuth 2.0 Token Exchange

- RFC 9068: JSON Web Token (JWT) Profile for OAuth 2.0 Access Tokens

## IPP Data File API

The IPP data file API provides functions to read and write IPP attributes and other commands or data using a common base format that supports tools such as `ipptool` and `ippeveprinter`.

### Creating an IPP Data File

The `ippFileNew` function creates a new IPP data file (`ipp_file_t`) object:

    ipp_file_t *parent = NULL;
    void *data;
    ipp_file_t *file = ippFileNew(parent, attr_cb, error_cb, data);

The "parent" IPP data file pointer is typically used to support nested files and is normally `NULL` for a new file. The "data" argument supplies your application data to the callbacks. The "attr_cb" callback function is used to filter IPP attributes; return `true` to include the attribute and `false` to ignore it:

    bool
    attr_cb(ipp_file_t *file, void *cb_data, const char *name)
    {
      ... determine whether to use an attribute named "name" ...
    }

The "error_cb" callback function is used to record/report errors when reading the file:

    bool
    error_cb(ipp_file_t *file, void *cb_data, const char *error)
    {
      ... display/record error and return `true` to continue or `false` to stop ...
    }

### Reading a Data File

The `ippFileOpen` function opens the specified data file and `ippFileRead` reads from it:

    if (ippFileOpen(file, "somefile", "r"))
    {
      // Opened successfully, now read it...
      ippFileRead(file, token_cb, /*with_groups*/false);
      ippFileClose(file);
    }

The token callback function passed to `ippFileRead` handles custom directives in your data file:

    bool
    token_cb(ipp_file_t *file, void *cb_data, const char *token)
    {
      ... handle token, return `true` to continue or `false` to stop ...
    }

The "token" parameter contains the token to be processed. The callback can use the `ippFileReadToken` function to read additional tokens from the file and the `ippFileExpandToken` function to expand any variables in the token string. Return `false` to stop reading the file and `true` to continue. The default `NULL` callback reports an unknown token error through the error callback end returns `false`.

Once read, you call the `ippFileGetAttributes` function to get the IPP attributes from the file.

### Variables

Each IPP data file object has associated variables that can be used when reading the file. The default set of variables is:

- "date-current": Current date in ISO-8601 format

- "date-start": Start date (when file opened) in ISO-8601 format

- "filename": Associated data/document filename, if any

- "filetype": MIME media type of associated data/document filename, if any

- "hostname": Hostname or IP address from the "uri" value, if any

- "port": Port number from the "uri" value, if any

- "resource": Resource path from the "uri" value, if any

- "scheme": URI scheme from the "uri" value, if any

- "uri": URI, if any

- "uriuser": Username from the "uri" value, if any

- "uripassword": Password from the "uri" value, if any

- "user": Current login user

The `ippFileGetVar`, `ippFileSetVar`, and `ippFileSetVarf` functions get and set file variables, respectively.

### Writing IPP Data Files

As when reading an IPP data file, the `ippFileNew` function creates a new file object, `ippFileOpen` opens the file, and `ippFileClose` closes the file. However, you call `ippFileWriteAttributes` to write the attributes in an IPP message (`ipp_t`), `ippFileWriteComment` to write a comment in the file, and `ippWriteToken` or `ippWriteTokenf` to write a token or value to the file.

## Migrating Code from CUPS 2.x and Earlier

The CUPS 3.x library removes all of the deprecated and obsolete APIs from CUPS 2.x and earlier and makes other naming changes for consistency. As a result, the CUPS 3.x library is no longer binary compatible with programs compiled against the CUPS 2.x library and earlier, and some source code may need minor changes to compile with the new library. This chapter describes the changes and how to migrate to the new library.

### General Changes

The following general changes have been made to the CUPS API:

- Boolean values now use the C99 `bool` type.

- Counts, indices, and lengths now use the `size_t` type - this affects the array, HTTP, IPP, and option APIs in particular.

- Accessor functions have been renamed (as necessary) to use the "get" and "set" verbs, for example `cupsServer` is now `cupsGetServer` and `httpEncryption` is now `httpSetEncryption`.

### Specific API Changes

- `cupsDoAuthentication` now returns a `bool` value - `true` on success or `false` on failure - instead of the old `int` values 0 and -1, respectively.

- `httpGets` now has the `http_t` pointer as the first argument.

- The `cups_size_t` structure now includes "color", "source", and "type" members to allow specification of media color, source (input tray/roll), and type.

- The `cups_encoding_t` enumeration values now use the `CUPS_ENCODING_` prefix for consistency with other enumerated types.

- X.509 certificates are now passed as C strings containing the PEM-encoded data instead of a `cups_array_t *` of raw data.

### Removed Functions and Types

The following CUPS 2.x API functions have been removed from the CUPS library:

- Old class/printer functions: `cupsGetClasses` and `cupsGetPrinters`.

- Accessor functions: `cupsEncryption`, `cupsLastError`, `cupsLastErrorString`, `cupsServer`, `cupsUser`, and `cupsUserAgent`.

- Array functions: `cupsArrayCount`, `cupsArrayFirst`, `cupsArrayIndex`, `cupsArrayLast`, `cupsArrayNew2`, `cupsArrayNew3`, `cupsArrayNext`, and `cupsArrayPrev`.

- File functions: `cupsFileCompression`, `cupsTempFd`, `cupsTempFile`, and `cupsTempFile2`.

- HTTP functions: `httpAddCredential`, `httpAddrAny`, `httpAddrEqual`, `httpAddrFamily`, `httpAddrLength`, `httpAddrLocalhost`, `httpAddrPort`, `httpAddrString`, `httpBlocking`, `httpCheck`, `httpCompareCredentials`, `httpConnectEncrypt`, `httpCopyCredentials`, `httpCreateCredentials`, `httpCredentialsAreValidForName`, `httpCredentialsGetExpiration`, `httpCredentialsGetTrust`, `httpCredentialsString`, `httpDecode64_2`, `httpDelete`, `httpEncode64_2`, `httpEncryption`, `httpError`, `httpFreeCredentials`, `httpGet`, `httpLoadCredentials`, `httpOptions`, `httpPost`, `httpPut`, `httpSaveCredentials`, `httpStatus`, and `httpTrace`.

- IPP functions: `ippFirstAttribute`, `ippLength`, `ippNextAttribute`, and `ippPort`.

- Localization functions: `cupsNotifySubject` and `cupsNotifyText`.

- PPD file functions: `ppdClose`, `ppdCollect`, `ppdCollect2`, `ppdConflicts`, `ppdEmit`, `ppdEmitAfterOrder`, `ppdEmitFd`, `ppdEmitJCL`, `ppdEmitJCLEnd`, `ppdEmitString`, `ppdErrorString`, `ppdFindAttr`, `ppdFindChoice`, `ppdFindCustomOption`, `ppdFindCustomParam`, `ppdFindMarkedChoice`, `ppdFindNextAttr`, `ppdFindOption`, `ppdFirstCustomParam`, `ppdFirstOption`, `ppdInstallableConflict`, `ppdIsMarked`, `ppdLastError`, `ppdLocalize`, `ppdLocalizeAttr`, `ppdLocalizeIPPReason`, `ppdLocalizeMarkerName`, `ppdMarkDefaults`, `ppdMarkOption`, `ppdNextCustomParam`, `ppdNextOption`, `ppdOpen`, `ppdOpen2`, `ppdOpenFd`, `ppdOpenFile`, `ppdPageLength`, `ppdPageSize`, `ppdPageSizeLimits`, `ppdPageWidth`, and `ppdSetConformance`.

- PPD helper functions: `cupsGetConflicts`, `cupsGetPPD`, `cupsGetPPD2`, `cupsGetPPD3`, `cupsGetServerPPD`, `cupsMarkOptions`, `cupsRasterInterpretPPD`, and `cupsResolveConflicts`.

- Non-destination print functions: `cupsCancelJob`, `cupsCancelJob2`, `cupsCreateJob`, `cupsCloseJob`, `cupsFinishDocument`, `cupsGetDefault`, `cupsGetDefault2`, `cupsPrintFile`, `cupsPrintFile2`, `cupsPrintFiles`, `cupsPrintFiles2`, and `cupsSendDocument`.

- Raster functions: `cupsRasterInitPWGHeader`.

Similarly, the following types have been removed from CUPS 3.0:

- Array types: `cups_acopy_func_t`, `cups_afree_func_t`, and `cups_array_func_t`.

- IPP types: `ipp_copycb_t` and `ipp_iocb_t`.

- Media types: `cups_size_t`.

- Raster types: `cups_mode_t` and `cups_raster_iocb_t`.

### Renamed Functions and Types

The following functions have been renamed in CUPS 3.0:

Old CUPS 2.x Name | New CUPS 3.0 Name
--- | ---
`cupsArrayNew3` | `cupsArrayNew`
`cupsAddDestMediaOptions2` | `cupsAddDestMediaOptions`
`cupsEncodeOptions2` | `cupsEncodeOptions`
`cupsGetDefault2` | `cupsGetDefault`
`cupsGetDestMediaByIndex2` | `cupsGetDestMediaByIndex`
`cupsGetDestMediaByName2` | `cupsGetDestMediaByName`
`cupsGetDestMediaBySize2` | `cupsGetDestMediaBySize`
`cupsGetDestMediaDefault2` | `cupsGetDestMediaDefault`
`cupsGetDests2` | `cupsGetDests`
`cupsGetJobs2` | `cupsGetJobs`
`cupsGetPassword2` | `cupsGetPassword`
`cupsLangGet` | `cupsLangFind`
`cupsLocalizeDestMedia2` | `cupsLocalizeDestMedia`
`cupsRasterReadHeader2` | `cupsRasterReadHeader`
`cupsRasterWriteHeader2` | `cupsRasterWriteHeader`
`cupsSetDests2` | `cupsSetDests`
`cupsSetPasswordCB2` | `cupsSetPasswordCB`
`httpAddrConnect2` | `httpAddrConnect2`
`httpConnect2` | `httpConnect`
`httpDecode64_3` | `httpDecode64`
`httpEncode64_3` | `httpEncode64`
`httpGetDateString2` | `httpGetDateString`
`httpGetLength2` | `httpGetLength`
`httpGetSubField2` | `httpGetSubField`
`httpGets2` | `httpGets`
`httpRead2` | `httpRead`
`httpReconnect2` | `httpConnectAgain`
`httpWrite2` | `httpWrite`

Similarly, the following types have been renamed in CUPS 3.0:

Old CUPS 2.x Name | New CUPS 3.0 Name
--- | ---
`cups_password_cb2_t` | `cups_password_cb_t`
`cups_page_header2_t` | `cups_page_header_t`

## Functions

### cupsAddDest

Add a destination to the list of destinations.

size_t cupsAddDest(const char *name, const char *instance, size_t num_dests, cups_dest_t **dests);

#### Parameters

name | Destination name
instance | Instance name or `NULL` for none/primary
num_dests | Number of destinations
dests | Destinations

#### Return Value

New number of destinations

#### Discussion

This function cannot be used to add a new class or printer queue, it only adds a new container of saved options for the named destination or instance.
If the named destination already exists, the destination list is returned unchanged. Adding a new instance of a destination creates a copy of that destination's options.
Use the `cupsSetDests` function to save the updated list of destinations to the user's lpoptions file.

### cupsAddDestMediaOptions

Add the option corresponding to the specified media size.

size_t cupsAddDestMediaOptions(http_t *http, cups_dest_t *dest, cups_dinfo_t *dinfo, unsigned flags, cups_media_t *media, size_t num_options, cups_option_t **options);

#### Parameters

http | Connection to destination
dest | Destination
dinfo | Destination information
flags | Media matching flags
media | Media
num_options | Current number of options
options | Options

#### Return Value

New number of options

### cupsAddIntegerOption

Add an integer option to an option array.

size_t cupsAddIntegerOption(const char *name, long value, size_t num_options, cups_option_t **options);

#### Parameters

name | Name of option
value | Value of option
num_options | Number of options
options | Pointer to options

#### Return Value

Number of options

#### Discussion

New option arrays can be initialized simply by passing 0 for the "num_options" argument.

### cupsAddOption

Add an option to an option array.

size_t cupsAddOption(const char *name, const char *value, size_t num_options, cups_option_t **options);

#### Parameters

name | Name of option
value | Value of option
num_options | Number of options
options | Pointer to options

#### Return Value

Number of options

#### Discussion

New option arrays can be initialized simply by passing 0 for the "num_options" argument.

### cupsAreCredentialsValidForName

Return whether the credentials are valid for the given name.

bool cupsAreCredentialsValidForName(const char *common_name, const char *credentials);

#### Parameters

common_name | Name to check
credentials | Credentials

#### Return Value

`true` if valid, `false` otherwise

### cupsArrayAdd

Add an element to an array.

bool cupsArrayAdd(cups_array_t *a, void *e);

#### Parameters

a | Array
e | Element

#### Return Value

`true` on success, `false` on failure

#### Discussion

This function adds an element to an array. When adding an element to a sorted array, non-unique elements are appended at the end of the run of identical elements. For unsorted arrays, the element is appended to the end of the array.

### cupsArrayAddStrings

Add zero or more delimited strings to an array.

bool cupsArrayAddStrings(cups_array_t *a, const char *s, char delim);

#### Parameters

a | Array
s | Delimited strings
delim | Delimiter character

#### Return Value

`true` on success, `false` on failure

#### Discussion

This function adds zero or more delimited strings to an array created using the `cupsArrayNewStrings` function. Duplicate strings are not added. If the string pointer "s" is `NULL` or the empty string, no strings are added to the array. If "delim" is the space character, then all whitespace is recognized as a delimiter.
Strings can be delimited by quotes ("foo", 'bar') and curly braces ("{foo}"), and characters can be escaped using the backslash () character. Outer quotes are stripped but inner ones are preserved.

### cupsArrayClear

Clear an array.

void cupsArrayClear(cups_array_t *a);

#### Parameters

a | Array

#### Discussion

This function is equivalent to removing all elements in the array, so the free callback (if any) is called for each element that is removed.

### cupsArrayDelete

Free all memory used by an array.

void cupsArrayDelete(cups_array_t *a);

#### Parameters

a | Array

#### Discussion

This function frees all memory used by an array. The free callback (if any) is called for each element in the array.

### cupsArrayDup

Duplicate an array.

cups_array_t *cupsArrayDup(cups_array_t *a);

#### Parameters

a | Array

#### Return Value

Duplicate array

### cupsArrayFind

Find an element in an array.

void *cupsArrayFind(cups_array_t *a, void *e);

#### Parameters

a | Array
e | Element

#### Return Value

Element found or `NULL`

### cupsArrayGetCount

Get the number of elements in an array.

size_t cupsArrayGetCount(cups_array_t *a);

#### Parameters

a | Array

#### Return Value

Number of elements

### cupsArrayGetCurrent

Return the current element in an array.

void *cupsArrayGetCurrent(cups_array_t *a);

#### Parameters

a | Array

#### Return Value

Element

#### Discussion

This function returns the current element in an array. The current element is undefined until you call `cupsArrayFind`, `cupsArrayGetElement`, `cupsArrayGetFirst`, or `cupsArrayGetLast`.

### cupsArrayGetElement

Get the N-th element in the array.

void *cupsArrayGetElement(cups_array_t *a, size_t n);

#### Parameters

a | Array
n | Index into array, starting at 0

#### Return Value

N-th element or `NULL`

### cupsArrayGetFirst

Get the first element in an array.

void *cupsArrayGetFirst(cups_array_t *a);

#### Parameters

a | Array

#### Return Value

First element or `NULL` if the array is empty

### cupsArrayGetIndex

Get the index of the current element.

size_t cupsArrayGetIndex(cups_array_t *a);

#### Parameters

a | Array

#### Return Value

Index of the current element, starting at 0

#### Discussion

This function returns the index of the current element or `SIZE_MAX` if there is no current element. The current element is undefined until you call `cupsArrayFind`, `cupsArrayGetElement`, `cupsArrayGetFirst`, or `cupsArrayGetLast`.

### cupsArrayGetInsert

Get the index of the last added or inserted element.

size_t cupsArrayGetInsert(cups_array_t *a);

#### Parameters

a | Array

#### Return Value

Index of the last added or inserted element, starting at 0

#### Discussion

This function returns the index of the last added or inserted element or `SIZE_MAX` if no elements have been added or inserted.

### cupsArrayGetLast

Get the last element in the array.

void *cupsArrayGetLast(cups_array_t *a);

#### Parameters

a | Array

#### Return Value

Last element or`NULL` if the array is empty

### cupsArrayGetNext

Get the next element in an array.

void *cupsArrayGetNext(cups_array_t *a);

#### Parameters

a | Array

#### Return Value

Next element or `NULL`

#### Discussion

This function returns the next element in an array. The next element is undefined until you call `cupsArrayFind`, `cupsArrayGetElement`, `cupsArrayGetFirst`, or `cupsArrayGetLast` to set the current element.

### cupsArrayGetPrev

Get the previous element in an array.

void *cupsArrayGetPrev(cups_array_t *a);

#### Parameters

a | Array

#### Return Value

Previous element or `NULL`

#### Discussion

This function returns the previous element in an array. The previous element is undefined until you call `cupsArrayFind`, `cupsArrayGetElement`, `cupsArrayGetFirst`, or `cupsArrayGetLast` to set the current element.

### cupsArrayGetUserData

Return the user data for an array.

void *cupsArrayGetUserData(cups_array_t *a);

#### Parameters

a | Array

#### Return Value

User data

### cupsArrayInsert

Insert an element in an array.

bool cupsArrayInsert(cups_array_t *a, void *e);

#### Parameters

a | Array
e | Element

#### Return Value

`true` on success, `false` on failure

#### Discussion

This function inserts an element in an array. When inserting an element in a sorted array, non-unique elements are inserted at the beginning of the run of identical elements. For unsorted arrays, the element is inserted at the beginning of the array.

### cupsArrayNew

Create a new array with callback functions.

cups_array_t *cupsArrayNew(cups_array_cb_t f, void *d, cups_ahash_cb_t hf, size_t hsize, cups_acopy_cb_t cf, cups_afree_cb_t ff);

#### Parameters

f | Comparison callback function or `NULL` for an unsorted array
d | User data or `NULL`
hf | Hash callback function or `NULL` for unhashed lookups
hsize | Hash size (>= `0`)
cf | Copy callback function or `NULL` for none
ff | Free callback function or `NULL` for none

#### Return Value

Array

#### Discussion

This function creates a new array with optional callback functions. The comparison callback function ("f") is used to create a sorted array. The function receives pointers to two elements and the user data pointer ("d"). The user data pointer argument can safely be omitted when not required so functions like `strcmp` can be used for sorted string arrays.

    int // Return -1 if a < b, 0 if a == b, and 1 if a > b
    compare_cb(void *a, void *b, void *d)
    {
      ... "a" and "b" are the elements, "d" is the user data pointer
    }

The hash callback function ("hf") is used to implement cached lookups with the specified hash size ("hsize"). The function receives a pointer to an element and the user data pointer ("d") and returns an unsigned integer representing a hash into the array. The hash value is of type `size_t` which provides at least 32-bits of resolution.

    size_t // Return hash value from 0 to (hashsize - 1)
    hash_cb(void *e, void *d)
    {
      ... "e" is the element, "d" is the user data pointer
    }

The copy callback function ("cf") is used to automatically copy/retain elements when added to the array or the array is copied with `cupsArrayDup`. The function receives a pointer to the element and the user data pointer ("d") and returns a new pointer that is stored in the array.

    void * // Return pointer to copied/retained element or NULL
    copy_cb(void *e, void *d)
    {
      ... "e" is the element, "d" is the user data pointer
    }

Finally, the free callback function ("cf") is used to automatically free/release elements when removed or the array is deleted. The function receives a pointer to the element and the user data pointer ("d").

    void
    free_cb(void *e, void *d)
    {
      ... "e" is the element, "d" is the user data pointer
    }

### cupsArrayNewStrings

Create a new array of delimited strings.

cups_array_t *cupsArrayNewStrings(const char *s, char delim);

#### Parameters

s | Delimited strings or `NULL` to create an empty array
delim | Delimiter character

#### Return Value

Array

#### Discussion

This function creates an array that holds zero or more strings. The created array automatically manages copies of the strings passed and sorts them in ascending order using a case-sensitive comparison. If the string pointer "s" is `NULL` or the empty string, no strings are added to the newly created array.
Additional strings can be added using the `cupsArrayAdd` or `cupsArrayAddStrings` functions.

### cupsArrayRemove

Remove an element from an array.

bool cupsArrayRemove(cups_array_t *a, void *e);

#### Parameters

a | Array
e | Element

#### Return Value

`true` on success, `false` on failure

#### Discussion

This function removes an element from an array. If more than one element matches "e", only the first matching element is removed.

### cupsArrayRestore

Reset the current element to the last `cupsArraySave`.

void *cupsArrayRestore(cups_array_t *a);

#### Parameters

a | Array

#### Return Value

New current element

### cupsArraySave

Mark the current element for a later `cupsArrayRestore`.

bool cupsArraySave(cups_array_t *a);

#### Parameters

a | Array

#### Return Value

`true` on success, `false` on failure

#### Discussion

The current element is undefined until you call `cupsArrayFind`, `cupsArrayGetElement`, `cupsArrayGetFirst`, or `cupsArrayGetLast` to set the current element.
The save/restore stack is guaranteed to be at least 32 elements deep.

### cupsCancelDestJob

Cancel a job on a destination.

ipp_status_t cupsCancelDestJob(http_t *http, cups_dest_t *dest, int job_id);

#### Parameters

http | Connection to destination
dest | Destination
job_id | Job ID

#### Return Value

Status of cancel operation

#### Discussion

This function cancels the specified job. The "dest" argument is the name of the destination printer while the "job_id" is the number returned by `cupsCreateDestJob`.
Returns `IPP_STATUS_OK` on success and `IPP_STATUS_ERROR_NOT_AUTHORIZED` or `IPP_STATUS_ERROR_FORBIDDEN` on failure.

### cupsCharsetToUTF8

Convert legacy character set to UTF-8.

ssize_t cupsCharsetToUTF8(char *dest, const char *src, const size_t maxout, const cups_encoding_t encoding);

#### Parameters

dest | Target string
src | Source string
maxout | Max output size in bytes
encoding | Encoding

#### Return Value

Number of bytes or `-1` on error

### cupsCheckDestSupported

Check that the option and value are supported by the destination.

bool cupsCheckDestSupported(http_t *http, cups_dest_t *dest, cups_dinfo_t *dinfo, const char *option, const char *value);

#### Parameters

http | Connection to destination
dest | Destination
dinfo | Destination information
option | Option
value | Value or `NULL`

#### Return Value

`true` if supported, `false` if not

#### Discussion

Returns 1 if supported, 0 otherwise.

### cupsCloseDestJob

Close a job and start printing.

ipp_status_t cupsCloseDestJob(http_t *http, cups_dest_t *dest, cups_dinfo_t *info, int job_id);

#### Parameters

http | Connection to destination
dest | Destination
info | Destination information
job_id | Job ID

#### Return Value

IPP status code

#### Discussion

This function closes a job and starts printing. Use when the last call to `cupsStartDestDocument` passed `false` for "last_document". "job_id" is the job ID returned by `cupsCreateDestJob`. Returns `IPP_STATUS_OK` on success.

### cupsConcatString

Safely concatenate two UTF-8 strings.

size_t cupsConcatString(char *dst, const char *src, size_t dstsize);

#### Parameters

dst | Destination string
src | Source string
dstsize | Size of destination string buffer

#### Return Value

Length of string

### cupsCondBroadcast

Wake up waiting threads.

void cupsCondBroadcast(cups_cond_t *cond);

#### Parameters

cond | Condition

### cupsCondDestroy

Destroy a condition variable.

void cupsCondDestroy(cups_cond_t *cond);

#### Parameters

cond | Condition

### cupsCondInit

Initialize a condition variable.

void cupsCondInit(cups_cond_t *cond);

#### Parameters

cond | Condition

### cupsCondWait

Wait for a condition with optional timeout.

void cupsCondWait(cups_cond_t *cond, cups_mutex_t *mutex, double timeout);

#### Parameters

cond | Condition
mutex | Mutex
timeout | Timeout in seconds (`0` or negative for none)

### cupsConnectDest

Open a connection to the destination.

http_t *cupsConnectDest(cups_dest_t *dest, unsigned flags, int msec, int *cancel, char *resource, size_t resourcesize, cups_dest_cb_t cb, void *user_data);

#### Parameters

dest | Destination
flags | Connection flags
msec | Timeout in milliseconds
cancel | Pointer to "cancel" variable
resource | Resource buffer
resourcesize | Size of resource buffer
cb | Callback function
user_data | User data pointer

#### Return Value

Connection to destination or `NULL`

#### Discussion

Connect to the destination, returning a new `http_t` connection object and optionally the resource path to use for the destination. These calls will block until a connection is made, the timeout expires, the integer pointed to by "cancel" is non-zero, or the callback function (or block) returns `0`. The caller is responsible for calling `httpClose` on the returned connection.
The caller can pass `CUPS_DEST_FLAGS_DEVICE` for the "flags" argument to connect directly to the device associated with the destination. Otherwise, the connection is made to the CUPS scheduler associated with the destination.

### cupsCopyCredentials

char *cupsCopyCredentials(const char *path, const char *common_name);

#### Parameters

path | Directory path for certificate/key store or `NULL` for default
common_name | Common name

#### Return Value

Copy the X.509 certificate chain to a string.

### cupsCopyCredentialsKey

Copy the private key to a string.

char *cupsCopyCredentialsKey(const char *path, const char *common_name);

#### Parameters

path | Directory path for certificate/key store or `NULL` for default
common_name | Common name

#### Return Value

PEM-encoded private key

### cupsCopyCredentialsPublicKey

Copy the public key for a X.509 certificate request.

char *cupsCopyCredentialsPublicKey(const char *path, const char *common_name);

#### Parameters

path | Directory path for certificate/key store or `NULL` for default
common_name | Common name

#### Return Value

PEM-encoded public key

### cupsCopyCredentialsRequest

Copy the X.509 certificate signing request to a string.

char *cupsCopyCredentialsRequest(const char *path, const char *common_name);

#### Parameters

path | Directory path for certificate/key store or `NULL` for default
common_name | Common name

#### Return Value

PEM-encoded X.509 certificate signing request

### cupsCopyDest

Copy a destination.

size_t cupsCopyDest(cups_dest_t *dest, size_t num_dests, cups_dest_t **dests);

#### Parameters

dest | Destination to copy
num_dests | Number of destinations
dests | Destination array

#### Return Value

New number of destinations

#### Discussion

Make a copy of the destination to an array of destinations (or just a single copy) - for use with the `cupsEnumDests*` functions. The caller is responsible for calling `cupsFreeDests` on the returned object(s).

### cupsCopyDestConflicts

Get conflicts and resolutions for a new option/value pair.

int cupsCopyDestConflicts(http_t *http, cups_dest_t *dest, cups_dinfo_t *dinfo, size_t num_options, cups_option_t *options, const char *new_option, const char *new_value, size_t *num_conflicts, cups_option_t **conflicts, size_t *num_resolved, cups_option_t **resolved);

#### Parameters

http | Connection to destination
dest | Destination
dinfo | Destination information
num_options | Number of current options
options | Current options
new_option | New option
new_value | New value
num_conflicts | Number of conflicting options
conflicts | Conflicting options
num_resolved | Number of options to resolve
resolved | Resolved options

#### Return Value

1 if there is a conflict, 0 if none, -1 on error

#### Discussion

"num_options" and "options" represent the currently selected options by the user. "new_option" and "new_value" are the setting the user has just changed.
Returns 1 if there is a conflict, 0 if there are no conflicts, and -1 if there was an unrecoverable error such as a resolver loop.
If "num_conflicts" and "conflicts" are not `NULL`, they are set to contain the list of conflicting option/value pairs. Similarly, if "num_resolved" and "resolved" are not `NULL` they will be set to the list of changes needed to resolve the conflict.
If cupsCopyDestConflicts returns 1 but "num_resolved" and "resolved" are set to 0 and `NULL`, respectively, then the conflict cannot be resolved.

### cupsCopyDestInfo

Get the supported values/capabilities for the destination.

cups_dinfo_t *cupsCopyDestInfo(http_t *http, cups_dest_t *dest, cups_dest_flags_t dflags);

#### Parameters

http | Connection to destination
dest | Destination
dflags | Destination flags

#### Return Value

Destination information

#### Discussion

The caller is responsible for calling `cupsFreeDestInfo` on the return value. `NULL` is returned on error.

### cupsCopyString

Safely copy a UTF-8 string.

size_t cupsCopyString(char *dst, const char *src, size_t dstsize);

#### Parameters

dst | Destination string
src | Source string
dstsize | Size of destination string buffer

#### Return Value

Length of string

### cupsCreateCredentials

Make an X.509 certificate and private key pair.

bool cupsCreateCredentials(const char *path, bool ca_cert, cups_credpurpose_t purpose, cups_credtype_t type, cups_credusage_t usage, const char *organization, const char *org_unit, const char *locality, const char *state_province, const char *country, const char *common_name, const char *email, size_t num_alt_names, const char *const *alt_names, const char *root_name, time_t expiration_date);

#### Parameters

path | Directory path for certificate/key store or `NULL` for default
ca_cert | `true` to create a CA certificate, `false` for a client/server certificate
purpose | Credential purposes
type | Credential type
usage | Credential usages
organization | Organization or `NULL` to use common name
org_unit | Organizational unit or `NULL` for none
locality | City/town or `NULL` for "Unknown"
state_province | State/province or `NULL` for "Unknown"
country | Country or `NULL` for locale-based default
common_name | Common name
email | Email address or `NULL` for none
num_alt_names | Number of subject alternate names
alt_names | Subject Alternate Names
root_name | Root certificate/domain name or `NULL` for site/self-signed
expiration_date | Expiration date

#### Return Value

`true` on success, `false` on failure

#### Discussion

This function creates an X.509 certificate and private key pair. The certificate and key are stored in the directory "path" or, if "path" is `NULL`, in a per-user or system-wide (when running as root) certificate/key store. The generated certificate is signed by the named root certificate or, if "root_name" is `NULL`, a site-wide default root certificate. When "root_name" is `NULL` and there is no site-wide default root certificate, a self-signed certificate is generated instead.
The "ca_cert" argument specifies whether a CA certificate should be created.
The "purpose" argument specifies the purpose(s) used for the credentials as a bitwise OR of the following constants:

- `CUPS_CREDPURPOSE_SERVER_AUTH` for validating TLS servers,
- `CUPS_CREDPURPOSE_CLIENT_AUTH` for validating TLS clients,
- `CUPS_CREDPURPOSE_CODE_SIGNING` for validating compiled code,
- `CUPS_CREDPURPOSE_EMAIL_PROTECTION` for validating email messages,
- `CUPS_CREDPURPOSE_TIME_STAMPING` for signing timestamps to objects, and/or
- `CUPS_CREDPURPOSE_OCSP_SIGNING` for Online Certificate Status Protocol message signing.

The "type" argument specifies the type of credentials using one of the following constants:

- `CUPS_CREDTYPE_DEFAULT`: default type (RSA-3072 or P-384),
- `CUPS_CREDTYPE_RSA_2048_SHA256`: RSA with 2048-bit keys and SHA-256 hash,
- `CUPS_CREDTYPE_RSA_3072_SHA256`: RSA with 3072-bit keys and SHA-256 hash,
- `CUPS_CREDTYPE_RSA_4096_SHA256`: RSA with 4096-bit keys and SHA-256 hash,
- `CUPS_CREDTYPE_ECDSA_P256_SHA256`: ECDSA using the P-256 curve with SHA-256 hash,
- `CUPS_CREDTYPE_ECDSA_P384_SHA256`: ECDSA using the P-384 curve with SHA-256 hash, or
- `CUPS_CREDTYPE_ECDSA_P521_SHA256`: ECDSA using the P-521 curve with SHA-256 hash.

The "usage" argument specifies the usage(s) for the credentials as a bitwise OR of the following constants:

- `CUPS_CREDUSAGE_DIGITAL_SIGNATURE`: digital signatures,
- `CUPS_CREDUSAGE_NON_REPUDIATION`: non-repudiation/content commitment,
- `CUPS_CREDUSAGE_KEY_ENCIPHERMENT`: key encipherment,
- `CUPS_CREDUSAGE_DATA_ENCIPHERMENT`: data encipherment,
- `CUPS_CREDUSAGE_KEY_AGREEMENT`: key agreement,
- `CUPS_CREDUSAGE_KEY_CERT_SIGN`: key certicate signing,
- `CUPS_CREDUSAGE_CRL_SIGN`: certificate revocation list signing,
- `CUPS_CREDUSAGE_ENCIPHER_ONLY`: encipherment only,
- `CUPS_CREDUSAGE_DECIPHER_ONLY`: decipherment only,
- `CUPS_CREDUSAGE_DEFAULT_CA`: defaults for CA certificates,
- `CUPS_CREDUSAGE_DEFAULT_TLS`: defaults for TLS certificates, and/or
- `CUPS_CREDUSAGE_ALL`: all usages.

The "organization", "org_unit", "locality", "state_province", and "country" arguments specify information about the identity and geolocation of the issuer.
The "common_name" argument specifies the common name and the "num_alt_names" and "alt_names" arguments specify a list of DNS hostnames for the certificate.
The "expiration_date" argument specifies the expiration date and time as a Unix `time_t` value in seconds.

### cupsCreateCredentialsRequest

Make an X.509 Certificate Signing Request.

bool cupsCreateCredentialsRequest(const char *path, cups_credpurpose_t purpose, cups_credtype_t type, cups_credusage_t usage, const char *organization, const char *org_unit, const char *locality, const char *state_province, const char *country, const char *common_name, const char *email, size_t num_alt_names, const char *const *alt_names);

#### Parameters

path | Directory path for certificate/key store or `NULL` for default
purpose | Credential purposes
type | Credential type
usage | Credential usages
organization | Organization or `NULL` to use common name
org_unit | Organizational unit or `NULL` for none
locality | City/town or `NULL` for "Unknown"
state_province | State/province or `NULL` for "Unknown"
country | Country or `NULL` for locale-based default
common_name | Common name
email | Email address or `NULL` for none
num_alt_names | Number of subject alternate names
alt_names | Subject Alternate Names

#### Return Value

`true` on success, `false` on error

#### Discussion

This function creates an X.509 certificate signing request (CSR) and associated private key. The CSR and key are stored in the directory "path" or, if "path" is `NULL`, in a per-user or system-wide (when running as root) certificate/key store.
The "purpose" argument specifies the purpose(s) used for the credentials as a bitwise OR of the following constants:

- `CUPS_CREDPURPOSE_SERVER_AUTH` for validating TLS servers,
- `CUPS_CREDPURPOSE_CLIENT_AUTH` for validating TLS clients,
- `CUPS_CREDPURPOSE_CODE_SIGNING` for validating compiled code,
- `CUPS_CREDPURPOSE_EMAIL_PROTECTION` for validating email messages,
- `CUPS_CREDPURPOSE_TIME_STAMPING` for signing timestamps to objects, and/or
- `CUPS_CREDPURPOSE_OCSP_SIGNING` for Online Certificate Status Protocol message signing.

The "type" argument specifies the type of credentials using one of the following constants:

- `CUPS_CREDTYPE_DEFAULT`: default type (RSA-3072 or P-384),
- `CUPS_CREDTYPE_RSA_2048_SHA256`: RSA with 2048-bit keys and SHA-256 hash,
- `CUPS_CREDTYPE_RSA_3072_SHA256`: RSA with 3072-bit keys and SHA-256 hash,
- `CUPS_CREDTYPE_RSA_4096_SHA256`: RSA with 4096-bit keys and SHA-256 hash,
- `CUPS_CREDTYPE_ECDSA_P256_SHA256`: ECDSA using the P-256 curve with SHA-256 hash,
- `CUPS_CREDTYPE_ECDSA_P384_SHA256`: ECDSA using the P-384 curve with SHA-256 hash, or
- `CUPS_CREDTYPE_ECDSA_P521_SHA256`: ECDSA using the P-521 curve with SHA-256 hash.

The "usage" argument specifies the usage(s) for the credentials as a bitwise OR of the following constants:

- `CUPS_CREDUSAGE_DIGITAL_SIGNATURE`: digital signatures,
- `CUPS_CREDUSAGE_NON_REPUDIATION`: non-repudiation/content commitment,
- `CUPS_CREDUSAGE_KEY_ENCIPHERMENT`: key encipherment,
- `CUPS_CREDUSAGE_DATA_ENCIPHERMENT`: data encipherment,
- `CUPS_CREDUSAGE_KEY_AGREEMENT`: key agreement,
- `CUPS_CREDUSAGE_KEY_CERT_SIGN`: key certicate signing,
- `CUPS_CREDUSAGE_CRL_SIGN`: certificate revocation list signing,
- `CUPS_CREDUSAGE_ENCIPHER_ONLY`: encipherment only,
- `CUPS_CREDUSAGE_DECIPHER_ONLY`: decipherment only,
- `CUPS_CREDUSAGE_DEFAULT_CA`: defaults for CA certificates,
- `CUPS_CREDUSAGE_DEFAULT_TLS`: defaults for TLS certificates, and/or
- `CUPS_CREDUSAGE_ALL`: all usages.

The "organization", "org_unit", "locality", "state_province", and "country" arguments specify information about the identity and geolocation of the issuer.
The "common_name" argument specifies the common name and the "num_alt_names" and "alt_names" arguments specify a list of DNS hostnames for the certificate.

### cupsCreateDestJob

Create a job on a destination.

ipp_status_t cupsCreateDestJob(http_t *http, cups_dest_t *dest, cups_dinfo_t *info, int *job_id, const char *title, size_t num_options, cups_option_t *options);

#### Parameters

http | Connection to destination
dest | Destination
info | Destination information
job_id | Job ID or `0` on error
title | Job name
num_options | Number of job options
options | Job options

#### Return Value

IPP status code

#### Discussion

This function creates a job on the specified destination "dest". The "info" argument contains information about the destination obtained using the `cupsCopyDestInfo` function.
The "job_id" argument provides an integer to hold the new job's ID number. The "title" argument provides the title of the job. The "num_options" and "options" arguments provide an array of job options for the job.
Returns `IPP_STATUS_OK` or `IPP_STATUS_OK_SUBST` on success, saving the job ID in the variable pointed to by "job_id".

### cupsCreateTempFd

Creates a temporary file.

int cupsCreateTempFd(const char *prefix, const char *suffix, char *filename, size_t len);

#### Parameters

prefix | Filename prefix or `NULL` for none
suffix | Filename suffix or `NULL` for none
filename | Pointer to buffer
len | Size of buffer

#### Return Value

New file descriptor or `-1` on error

#### Discussion

This function creates a temporary file and returns a file descriptor for the file. The unique temporary filename uses the "prefix" and "suffix" arguments and is returned in the filename buffer. The temporary file is opened for reading and writing.

### cupsCreateTempFile

Creates a temporary CUPS file.

cups_file_t *cupsCreateTempFile(const char *prefix, const char *suffix, char *filename, size_t len);

#### Parameters

prefix | Filename prefix or `NULL` for none
suffix | Filename suffix or `NULL` for none
filename | Pointer to buffer
len | Size of buffer

#### Return Value

CUPS file or `NULL` on error

#### Discussion

This function creates a temporary file and returns a file descriptor for the file. The unique temporary filename uses the "prefix" and "suffix" arguments and is returned in the filename buffer. The temporary file is opened for writing.

### cupsDNSSDAssembleFullName

Create a full service name from the instance name, registration type, and domain.

bool cupsDNSSDAssembleFullName(char *fullname, size_t fullsize, const char *name, const char *type, const char *domain);

#### Parameters

fullname | Buffer for full name
fullsize | Size of buffer
name | Service instance name
type | Registration type
domain | Domain

#### Return Value

`true` on success, `false` on failure

#### Discussion

This function combines an instance name ("Example Name"), registration type ("_ipp._tcp"), and domain ("local.") to create a properly escaped full service name ("Example032Name._ipp._tcp.local.").

### cupsDNSSDBrowseDelete

Cancel and delete a browse request.

void cupsDNSSDBrowseDelete(cups_dnssd_browse_t *browse);

#### Parameters

browse | Browse request

### cupsDNSSDBrowseGetContext

Get the DNS-SD context for the browse request.

cups_dnssd_t *cupsDNSSDBrowseGetContext(cups_dnssd_browse_t *browse);

#### Parameters

browse | Browse request

#### Return Value

Context or `NULL`

### cupsDNSSDBrowseNew

Create a new DNS-SD browse request.

cups_dnssd_browse_t *cupsDNSSDBrowseNew(cups_dnssd_t *dnssd, uint32_t if_index, const char *types, const char *domain, cups_dnssd_browse_cb_t browse_cb, void *cb_data);

#### Parameters

dnssd | DNS-SD context
if_index | Interface index, `CUPS_DNSSD_IF_INDEX_ANY`, or `CUPS_DNSSD_IF_INDEX_LOCAL`
types | Service types
domain | Domain name or `NULL` for default
browse_cb | Browse callback function
cb_data | Browse callback data

#### Return Value

Browse request or `NULL` on error

#### Discussion

This function creates a new DNS-SD browse request for the specified service types and optional domain and interface index. The "types" argument can be a single service type ("_ipp._tcp") or a service type and comma-delimited list of sub-types ("_ipp._tcp,_print,_universal").
Newly discovered services are reported using the required browse callback function, with the "flags" argument set to `CUPS_DNSSD_FLAGS_ADD` for newly discovered services, `CUPS_DNSSD_FLAGS_NONE` for removed services, or `CUPS_DNSSD_FLAGS_ERROR` on an error:

    void
    browse_cb(
        cups_dnssd_browse_t *browse,
        void                *cb_data,
        cups_dnssd_flags_t  flags,
        uint32_t            if_index,
        const char          *name,
        const char          *regtype,
        const char          *domain)
    {
        // Process added/removed service
    }

### cupsDNSSDCopyComputerName

Copy the current human-readable name for the system.

char *cupsDNSSDCopyComputerName(cups_dnssd_t *dnssd, char *buffer, size_t bufsize);

#### Parameters

dnssd | DNS-SD context
buffer | Computer name buffer
bufsize | Size of computer name buffer (at least 128 bytes)

#### Return Value

Computer name or `NULL` on error

#### Discussion

This function copies the current human-readable name ("My Computer") to the provided buffer. The "dnssd" argument is a DNS-SD context created with `cupsDNSSDNew`. The "buffer" argument points to a character array of at least 128 bytes and the "bufsize" argument specifies the actual size of the array.

### cupsDNSSDCopyHostName

Copy the current mDNS hostname for the system.

char *cupsDNSSDCopyHostName(cups_dnssd_t *dnssd, char *buffer, size_t bufsize);

#### Parameters

dnssd | DNS-SD context
buffer | Hostname buffer
bufsize | Size of hostname buffer (at least 70 bytes)

#### Return Value

mDNS hostname or `NULL` on error

#### Discussion

This function copies the current mDNS hostname ("hostname.local") to the provided buffer. The "dnssd" argument is a DNS-SD context created with `cupsDNSSDNew`. The "buffer" argument points to a character array of at least 70 bytes and the "bufsize" argument specifies the actual size of the array.

### cupsDNSSDDecodeTXT

Decode a TXT record into key/value pairs.

size_t cupsDNSSDDecodeTXT(const unsigned char *txtrec, uint16_t txtlen, cups_option_t **txt);

#### Parameters

txtrec | TXT record data
txtlen | TXT record length
txt | Key/value pairs

#### Return Value

Number of key/value pairs

#### Discussion

This function converts the DNS TXT record encoding of key/value pairs into `cups_option_t` elements that can be accessed using the `cupsGetOption` function and freed using the `cupsFreeOptions` function.

### cupsDNSSDDelete

Delete a DNS-SD context and all its requests.

void cupsDNSSDDelete(cups_dnssd_t *dnssd);

#### Parameters

dnssd | DNS-SD context

### cupsDNSSDGetConfigChanges

Get the number of host name/network configuration changes seen.

size_t cupsDNSSDGetConfigChanges(cups_dnssd_t *dnssd);

#### Parameters

dnssd | DNS-SD context

#### Return Value

Number of host name changes

#### Discussion

This function returns the number of host name or network configuration changes that have been seen since the context was created. The value can be used to track when local services need to be updated. Registered services will also get a callback with the `CUPS_DNSSD_FLAGS_HOST_CHANGE` bit set in the "flags" argument for host name changes and/or `CUPS_DNSSD_FLAGS_NETWORK_CHANGE` for network changes.

### cupsDNSSDNew

Create a new DNS-SD context.

cups_dnssd_t *cupsDNSSDNew(cups_dnssd_error_cb_t error_cb, void *cb_data);

#### Parameters

error_cb | Error callback function
cb_data | Error callback data

#### Return Value

DNS-SD context

#### Discussion

This function creates a new DNS-SD context for browsing, querying, resolving, and/or registering services. Call `cupsDNSSDDelete` to stop any pending browses, queries, or resolves, unregister any services, and free the DNS-SD context.

### cupsDNSSDQueryDelete

Cancel and delete a query request.

void cupsDNSSDQueryDelete(cups_dnssd_query_t *query);

#### Parameters

query | Query request

### cupsDNSSDQueryGetContext

Get the DNS-SD context for the query request.

cups_dnssd_t *cupsDNSSDQueryGetContext(cups_dnssd_query_t *query);

#### Parameters

query | Query request

#### Return Value

DNS-SD context or `NULL`

### cupsDNSSDQueryNew

Create a new query request.

cups_dnssd_query_t *cupsDNSSDQueryNew(cups_dnssd_t *dnssd, uint32_t if_index, const char *fullname, uint16_t rrtype, cups_dnssd_query_cb_t query_cb, void *cb_data);

#### Parameters

dnssd | DNS-SD context
if_index | Interface index or `CUPS_DNSSD_IF_INDEX_ANY` or `CUPS_DNSSD_IF_INDEX_LOCAL`
fullname | Full DNS name including types and domain
rrtype | Record type to query (`CUPS_DNSSD_RRTYPE_TXT`, etc.)
query_cb | Query callback function
cb_data | Query callback data

#### Return Value

Query request or `NULL` on error

#### Discussion

This function creates a new DNS-SD query request for the specified full service name and DNS record type. The "fullname" argument specifies the full DNS name of the service (instance name, type, and domain) being queried. Responses to the query are reported using the required query callback function with the "flags" argument set to `CUPS_DNSSD_FLAGS_NONE` on success or `CUPS_DNSSD_FLAGS_ERROR` on error:

    void
    query_cb(
        cups_dnssd_query_t *query,
        void               *cb_data,
        cups_dnssd_flags_t flags,
        uint32_t           if_index,
        const char         *fullname,
        uint16_t           rrtype,
        const void         *qdata,
        uint16_t           qlen)
    {
        // Process query record
    }

### cupsDNSSDResolveDelete

Cancel and free a resolve request.

void cupsDNSSDResolveDelete(cups_dnssd_resolve_t *res);

#### Parameters

res | Resolve request

### cupsDNSSDResolveGetContext

Get the DNS-SD context for the resolve request.

cups_dnssd_t *cupsDNSSDResolveGetContext(cups_dnssd_resolve_t *resolve);

#### Parameters

resolve | Resolve request

#### Return Value

DNS-SD context or `NULL`

### cupsDNSSDResolveNew

Create a new DNS-SD resolve request.

cups_dnssd_resolve_t *cupsDNSSDResolveNew(cups_dnssd_t *dnssd, uint32_t if_index, const char *name, const char *type, const char *domain, cups_dnssd_resolve_cb_t resolve_cb, void *cb_data);

#### Parameters

dnssd | DNS-SD context
if_index | Interface index or `CUPS_DNSSD_IF_INDEX_ANY` or `CUPS_DNSSD_IF_INDEX_LOCAL`
name | Service name
type | Service type
domain | Domain name or `NULL` for default
resolve_cb | Resolve callback function
cb_data | Resolve callback data

#### Return Value

Resolve request or `NULL` on error

#### Discussion

This function creates a new DNS-SD resolver for the specified instance name, service type, and optional domain and interface index. Resikved services are reported using the required resolve callback function, with the "flags" argument set to `CUPS_DNSSD_FLAGS_NONE` on success or `CUPS_DNSSD_FLAGS_ERROR` on error:

    void
    resolve_cb(
        cups_dnssd_resolve_t *resolve,
        void                 *cb_data,
        cups_dnssd_flags_t   flags,
        uint32_t             if_index,
        const char           *fullname,
        const char           *host,
        uint16_t             port,
        size_t               num_txt,
        cups_option_t        *txt)
    {
        // Process resolved service
    }

### cupsDNSSDSeparateFullName

Separate a full service name into an instance name, registration type, and domain.

bool cupsDNSSDSeparateFullName(const char *fullname, char *name, size_t namesize, char *type, size_t typesize, char *domain, size_t domainsize);

#### Parameters

fullname | Full service name
name | Instance name buffer
namesize | Size of instance name buffer
type | Registration type buffer
typesize | Size of registration type buffer
domain | Domain name buffer
domainsize | Size of domain name buffer

#### Return Value

`true` on success, `false` on error

#### Discussion

This function separates a full service name such as "Example032Name._ipp._tcp.local.") into its instance name ("Example Name"), registration type ("_ipp._tcp"), and domain ("local.").

### cupsDNSSDServiceAdd

Add a service instance.

bool cupsDNSSDServiceAdd(cups_dnssd_service_t *service, const char *types, const char *domain, const char *host, uint16_t port, size_t num_txt, cups_option_t *txt);

#### Parameters

service | Service
types | Service types
domain | Domain name or `NULL` for default
host | Host name or `NULL` for default
port | Port number or `0` for none
num_txt | Number of TXT record values
txt | TXT record values

#### Return Value

`true` on success, `false` on failure

#### Discussion

This function adds a service instance for the specified service types, domain, host, and port. The "types" argument can be a single service type ("_ipp._tcp") or a service type and comma-delimited list of sub-types ("_ipp._tcp,_print,_universal").
Call the `cupsDNSSDServicePublish` function after all service instances have been added.

### cupsDNSSDServiceDelete

Cancel and free a service registration.

void cupsDNSSDServiceDelete(cups_dnssd_service_t *service);

#### Parameters

service | Service

### cupsDNSSDServiceGetContext

Get the DNS-SD context for the service registration.

cups_dnssd_t *cupsDNSSDServiceGetContext(cups_dnssd_service_t *service);

#### Parameters

service | Service registration

#### Return Value

DNS-SD context or `NULL`

### cupsDNSSDServiceGetName

Get the service instance name for the service registration.

const char *cupsDNSSDServiceGetName(cups_dnssd_service_t *service);

#### Parameters

service | Service registration

#### Return Value

Service instance name

### cupsDNSSDServiceNew

Create a new named service.

cups_dnssd_service_t *cupsDNSSDServiceNew(cups_dnssd_t *dnssd, uint32_t if_index, const char *name, cups_dnssd_service_cb_t cb, void *cb_data);

#### Parameters

dnssd | DNS-SD context
if_index | Interface index, `CUPS_DNSSD_IF_INDEX_ANY`, or `CUPS_DNSSD_IF_INDEX_LOCAL`
name | Name of service
cb | Service registration callback function
cb_data | Service registration callback data

#### Return Value

Service or `NULL` on error

#### Discussion

This function creates a new DNS-SD service registration for the given service instance name and interface. Specific services using the name are added using the `cupsDNSSDServiceAdd` function.
The required service callback is called for select events, with the "flags" argument set to `CUPS_DNSSD_FLAGS_NONE` for a successful registration, `CUPS_DNSSD_FLAGS_COLLISION` when there is a name collision, or `CUPS_DNSSD_FLAGS_ERROR` when there is a problem completing the service registration.

### cupsDNSSDServicePublish

Publish a service.

bool cupsDNSSDServicePublish(cups_dnssd_service_t *service);

#### Parameters

service | Service

#### Return Value

`true` on success, `false` on failure

#### Discussion

This function publishes the DNS-SD services added using the `cupsDNSSDServiceAdd` function.

### cupsDNSSDServiceSetLocation

Set the geolocation (LOC record) of a service.

bool cupsDNSSDServiceSetLocation(cups_dnssd_service_t *service, const char *geo_uri);

#### Parameters

service | Service
geo_uri | Geolocation as a 'geo:' URI

#### Return Value

`true` on success, `false` on failure

#### Discussion

This function sets the geolocation of a service using a 'geo:' URI (RFC 5870) of the form 'geo:LATITUDE,LONGITUDE[,ALTITUDE][;crs=CRSLABEL][;u=UNCERTAINTY]'. The specified coordinates and uncertainty are converted into a DNS LOC record for the service name label. Only the "wgs84" CRSLABEL string is supported.
You must call this function prior to `cupsDNSSDServiceAdd`.

### cupsDirClose

Close a directory.

void cupsDirClose(cups_dir_t *dp);

#### Parameters

dp | Directory pointer

### cupsDirOpen

Open a directory.

cups_dir_t *cupsDirOpen(const char *directory);

#### Parameters

directory | Directory name

#### Return Value

Directory pointer or `NULL` if the directory could not be opened.

### cupsDirRead

Read the next directory entry.

cups_dentry_t *cupsDirRead(cups_dir_t *dp);

#### Parameters

dp | Directory pointer

#### Return Value

Directory entry or `NULL` when there are no more

### cupsDirRewind

Rewind to the start of the directory.

void cupsDirRewind(cups_dir_t *dp);

#### Parameters

dp | Directory pointer

### cupsDoAuthentication

Authenticate a request.

bool cupsDoAuthentication(http_t *http, const char *method, const char *resource);

#### Parameters

http | Connection to server or `CUPS_HTTP_DEFAULT`
method | Request method ("GET", "POST", "PUT")
resource | Resource path

#### Return Value

`true` on success, `false` on failure/error

#### Discussion

This function performs authentication for a request. It should be called in response to a `HTTP_STATUS_UNAUTHORIZED` status, prior to resubmitting your request.

### cupsDoFileRequest

Do an IPP request with a file.

ipp_t *cupsDoFileRequest(http_t *http, ipp_t *request, const char *resource, const char *filename);

#### Parameters

http | Connection to server or `CUPS_HTTP_DEFAULT`
request | IPP request
resource | HTTP resource for POST
filename | File to send or `NULL` for none

#### Return Value

Response data

#### Discussion

This function sends the IPP request and attached file to the specified server, retrying and authenticating as necessary. The request is freed with `ippDelete`.

### cupsDoIORequest

Do an IPP request with file descriptors.

ipp_t *cupsDoIORequest(http_t *http, ipp_t *request, const char *resource, int infile, int outfile);

#### Parameters

http | Connection to server or `CUPS_HTTP_DEFAULT`
request | IPP request
resource | HTTP resource for POST
infile | File to read from or `-1` for none
outfile | File to write to or `-1` for none

#### Return Value

Response data

#### Discussion

This function sends the IPP request with the optional input file "infile" to the specified server, retrying and authenticating as necessary. The request is freed with `ippDelete`.
If "infile" is a valid file descriptor, `cupsDoIORequest` copies all of the data from the file after the IPP request message.
If "outfile" is a valid file descriptor, `cupsDoIORequest` copies all of the data after the IPP response message to the file.

### cupsDoRequest

Do an IPP request.

ipp_t *cupsDoRequest(http_t *http, ipp_t *request, const char *resource);

#### Parameters

http | Connection to server or `CUPS_HTTP_DEFAULT`
request | IPP request
resource | HTTP resource for POST

#### Return Value

Response data

#### Discussion

This function sends the IPP request to the specified server, retrying and authenticating as necessary. The request is freed with `ippDelete`.

### cupsEncodeOption

Encode a single option into an IPP attribute.

ipp_attribute_t *cupsEncodeOption(ipp_t *ipp, ipp_tag_t group_tag, const char *name, const char *value);

#### Parameters

ipp | IPP request/response
group_tag | Attribute group
name | Option name
value | Option string value

#### Return Value

New attribute or `NULL` on error

### cupsEncodeOptions

Encode printer options into IPP attributes for a group.

void cupsEncodeOptions(ipp_t *ipp, size_t num_options, cups_option_t *options, ipp_tag_t group_tag);

#### Parameters

ipp | IPP request/response
num_options | Number of options
options | Options
group_tag | Group to encode

#### Discussion

This function encodes options as IPP attributes for a single group. Call this function multiple times for each group as needed.

### cupsEncodingString

Return the character encoding name string for the given encoding enumeration.

const char *cupsEncodingString(cups_encoding_t value);

#### Parameters

value | Encoding value

#### Return Value

Character encoding string

### cupsEncodingValue

Return the encoding enumeration value for a given character encoding name string.

cups_encoding_t cupsEncodingValue(const char *s);

#### Parameters

s | Character encoding string

#### Return Value

Encoding value

### cupsEnumDests

Enumerate available destinations with a callback function.

bool cupsEnumDests(unsigned flags, int msec, int *cancel, cups_ptype_t type, cups_ptype_t mask, cups_dest_cb_t cb, void *user_data);

#### Parameters

flags | Enumeration flags
msec | Timeout in milliseconds, -1 for indefinite
cancel | Pointer to "cancel" variable
type | Printer type bits
mask | Mask for printer type bits
cb | Callback function
user_data | User data

#### Return Value

`true` on success, `false` on failure

#### Discussion

Destinations are enumerated from one or more sources. The callback function receives the "user_data" pointer and the destination pointer which can be used as input to the `cupsCopyDest` function. The function must return `true` to continue enumeration or `false` to stop.
The "type" and "mask" arguments allow the caller to filter the destinations that are enumerated. Passing `0` for both will enumerate all printers. The constant `CUPS_PTYPE_DISCOVERED` is used to filter on destinations that are available but have not yet been added locally.
Enumeration happens on the current thread and does not return until all destinations have been enumerated or the callback function returns `false`.
Note: The callback function will likely receive multiple updates for the same destinations - it is up to the caller to suppress any duplicate destinations.

### cupsFileClose

Close a CUPS file.

bool cupsFileClose(cups_file_t *fp);

#### Parameters

fp | CUPS file

#### Return Value

`true` on success, `false` on error

### cupsFileEOF

Return the end-of-file status.

bool cupsFileEOF(cups_file_t *fp);

#### Parameters

fp | CUPS file

#### Return Value

`true` on end of file, `false` otherwise

### cupsFileFind

Find a file using the specified path.

const char *cupsFileFind(const char *filename, const char *path, bool executable, char *buffer, size_t bufsize);

#### Parameters

filename | File to find
path | Colon/semicolon-separated path
executable | `true` = executable files, `false` = any file/dir
buffer | Filename buffer
bufsize | Size of filename buffer

#### Return Value

Full path to file or `NULL` if not found

#### Discussion

This function allows the paths in the path string to be separated by colons (POSIX standard) or semicolons (Windows standard) and stores the result in the buffer supplied. If the file cannot be found in any of the supplied paths, `NULL` is returned. A `NULL` path only matches the current directory.

### cupsFileFlush

Flush pending output.

bool cupsFileFlush(cups_file_t *fp);

#### Parameters

fp | CUPS file

#### Return Value

`true` on success, `false` on error

### cupsFileGetChar

Get a single character from a file.

int cupsFileGetChar(cups_file_t *fp);

#### Parameters

fp | CUPS file

#### Return Value

Character or `-1` on end of file

### cupsFileGetConf

Get a line from a configuration file.

char *cupsFileGetConf(cups_file_t *fp, char *buf, size_t buflen, char **value, int *linenum);

#### Parameters

fp | CUPS file
buf | String buffer
buflen | Size of string buffer
value | Pointer to value
linenum | Current line number

#### Return Value

Line read or `NULL` on end of file or error

### cupsFileGetLine

Get a CR and/or LF-terminated line that may contain binary data.

size_t cupsFileGetLine(cups_file_t *fp, char *buf, size_t buflen);

#### Parameters

fp | File to read from
buf | Buffer
buflen | Size of buffer

#### Return Value

Number of bytes on line or 0 on end of file

#### Discussion

This function differs from `cupsFileGets` in that the trailing CR and LF are preserved, as is any binary data on the line. The buffer is `nul`-terminated, however you should use the returned length to determine the number of bytes on the line.

### cupsFileGets

Get a CR and/or LF-terminated line.

char *cupsFileGets(cups_file_t *fp, char *buf, size_t buflen);

#### Parameters

fp | CUPS file
buf | String buffer
buflen | Size of string buffer

#### Return Value

Line read or `NULL` on end of file or error

### cupsFileIsCompressed

Return whether a file is compressed.

bool cupsFileIsCompressed(cups_file_t *fp);

#### Parameters

fp | CUPS file

#### Return Value

`true` if compressed, `false` if not

### cupsFileLock

Temporarily lock access to a file.

bool cupsFileLock(cups_file_t *fp, bool block);

#### Parameters

fp | CUPS file
block | `true` to wait for the lock, `false` to fail right away

#### Return Value

`true` on success, `false` on error

### cupsFileNumber

Return the file descriptor associated with a CUPS file.

int cupsFileNumber(cups_file_t *fp);

#### Parameters

fp | CUPS file

#### Return Value

File descriptor

### cupsFileOpen

Open a CUPS file.

cups_file_t *cupsFileOpen(const char *filename, const char *mode);

#### Parameters

filename | Name of file
mode | Open mode

#### Return Value

CUPS file or `NULL` if the file or socket cannot be opened

#### Discussion

This function opens a file or socket for use with the CUPS file API.
The "filename" argument is a filename or socket address.
The "mode" argument can be "r" to read, "w" to write, overwriting any existing file, "a" to append to an existing file or create a new file, or "s" to open a socket connection.
When opening for writing ("w"), an optional number from `1` to `9` can be supplied which enables Flate compression of the file. Compression is not supported for the "a" (append) mode.
When opening for writing ("w") or append ("a"), an optional 'm###' suffix can be used to set the permissions of the opened file.
When opening a socket connection, the filename is a string of the form "address:port" or "hostname:port". The socket will make an IPv4 or IPv6 connection as needed, generally preferring IPv6 connections when there is a choice.

### cupsFileOpenFd

Open a CUPS file using a file descriptor.

cups_file_t *cupsFileOpenFd(int fd, const char *mode);

#### Parameters

fd | File descriptor
mode | Open mode

#### Return Value

CUPS file or `NULL` if the file could not be opened

#### Discussion

This function prepares a file descriptor for use with the CUPS file API.
The "fd" argument specifies the file descriptor.
The "mode" argument can be "r" to read, "w" to write, "a" to append, or "s" to treat the file descriptor as a bidirectional socket connection.
When opening for writing ("w"), an optional number from `1` to `9` can be supplied which enables Flate compression of the file. Compression is not supported for the "a" (append) mode.

### cupsFilePeekChar

Peek at the next character from a file.

int cupsFilePeekChar(cups_file_t *fp);

#### Parameters

fp | CUPS file

#### Return Value

Character or `-1` on end of file

### cupsFilePrintf

Write a formatted string.

bool cupsFilePrintf(cups_file_t *fp, const char *format, ...);

#### Parameters

fp | CUPS file
format | Printf-style format string
... | Additional args as necessary

#### Return Value

`true` on success, `false` on error

### cupsFilePutChar

Write a character.

bool cupsFilePutChar(cups_file_t *fp, int c);

#### Parameters

fp | CUPS file
c | Character to write

#### Return Value

`true` on success, `false` on error

### cupsFilePutConf

Write a configuration line.

bool cupsFilePutConf(cups_file_t *fp, const char *directive, const char *value);

#### Parameters

fp | CUPS file
directive | Directive
value | Value

#### Return Value

`true` on success, `false` on error

#### Discussion

This function handles any comment escaping of the value.

### cupsFilePuts

Write a string.

bool cupsFilePuts(cups_file_t *fp, const char *s);

#### Parameters

fp | CUPS file
s | String to write

#### Return Value

`true` on success, `false` on error

#### Discussion

Like the `fputs` function, no newline is appended to the string.

### cupsFileRead

Read from a file.

ssize_t cupsFileRead(cups_file_t *fp, char *buf, size_t bytes);

#### Parameters

fp | CUPS file
buf | Buffer
bytes | Number of bytes to read

#### Return Value

Number of bytes read or -1 on error

### cupsFileRewind

Set the current file position to the beginning of the file.

off_t cupsFileRewind(cups_file_t *fp);

#### Parameters

fp | CUPS file

#### Return Value

New file position or `-1` on error

### cupsFileSeek

Seek in a file.

off_t cupsFileSeek(cups_file_t *fp, off_t pos);

#### Parameters

fp | CUPS file
pos | Position in file

#### Return Value

New file position or `-1` on error

### cupsFileStderr

Return a CUPS file associated with stderr.

cups_file_t *cupsFileStderr(void);

#### Return Value

CUPS file

### cupsFileStdin

Return a CUPS file associated with stdin.

cups_file_t *cupsFileStdin(void);

#### Return Value

CUPS file

### cupsFileStdout

Return a CUPS file associated with stdout.

cups_file_t *cupsFileStdout(void);

#### Return Value

CUPS file

### cupsFileTell

Return the current file position.

off_t cupsFileTell(cups_file_t *fp);

#### Parameters

fp | CUPS file

#### Return Value

File position

### cupsFileUnlock

Unlock access to a file.

bool cupsFileUnlock(cups_file_t *fp);

#### Parameters

fp | CUPS file

#### Return Value

`true` on success, `false` on error

### cupsFileWrite

Write to a file.

bool cupsFileWrite(cups_file_t *fp, const char *buf, size_t bytes);

#### Parameters

fp | CUPS file
buf | Buffer
bytes | Number of bytes to write

#### Return Value

`true` on success, `false` on error

### cupsFindDestDefault

Find the default value(s) for the given option.

ipp_attribute_t *cupsFindDestDefault(http_t *http, cups_dest_t *dest, cups_dinfo_t *dinfo, const char *option);

#### Parameters

http | Connection to destination
dest | Destination
dinfo | Destination information
option | Option/attribute name

#### Return Value

Default attribute or `NULL` for none

#### Discussion

The returned value is an IPP attribute. Use the `ippGetBoolean`, `ippGetCollection`, `ippGetCount`, `ippGetDate`, `ippGetInteger`, `ippGetOctetString`, `ippGetRange`, `ippGetResolution`, `ippGetString`, and `ippGetValueTag` functions to inspect the default value(s) as needed.

### cupsFindDestReady

Find the default value(s) for the given option.

ipp_attribute_t *cupsFindDestReady(http_t *http, cups_dest_t *dest, cups_dinfo_t *dinfo, const char *option);

#### Parameters

http | Connection to destination
dest | Destination
dinfo | Destination information
option | Option/attribute name

#### Return Value

Default attribute or `NULL` for none

#### Discussion

The returned value is an IPP attribute. Use the `ippGetBoolean`, `ippGetCollection`, `ippGetCount`, `ippGetDate`, `ippGetInteger`, `ippGetOctetString`, `ippGetRange`, `ippGetResolution`, `ippGetString`, and `ippGetValueTag` functions to inspect the default value(s) as needed.

### cupsFindDestSupported

Find the default value(s) for the given option.

ipp_attribute_t *cupsFindDestSupported(http_t *http, cups_dest_t *dest, cups_dinfo_t *dinfo, const char *option);

#### Parameters

http | Connection to destination
dest | Destination
dinfo | Destination information
option | Option/attribute name

#### Return Value

Default attribute or `NULL` for none

#### Discussion

The returned value is an IPP attribute. Use the `ippGetBoolean`, `ippGetCollection`, `ippGetCount`, `ippGetDate`, `ippGetInteger`, `ippGetOctetString`, `ippGetRange`, `ippGetResolution`, `ippGetString`, and `ippGetValueTag` functions to inspect the default value(s) as needed.

### cupsFinishDestDocument

Finish the current document.

ipp_status_t cupsFinishDestDocument(http_t *http, cups_dest_t *dest, cups_dinfo_t *info);

#### Parameters

http | Connection to destination
dest | Destination
info | Destination information

#### Return Value

Status of document submission

#### Discussion

This function finished the current document for a job on the specified destination "dest". The "info" argument contains information about the destination obtained using the `cupsCopyDestInfo` function.
Returns `IPP_STATUS_OK` or `IPP_STATUS_OK_SUBST` on success.

### cupsFormDecode

Decode URL-encoded form data.

size_t cupsFormDecode(const char *data, cups_option_t **vars);

#### Parameters

data | URL-encoded form data
vars | Array of variables

#### Return Value

Number of variables

#### Discussion

This function decodes URL-encoded form data, returning the number of variables and a pointer to a `cups_option_t` array of the variables.
Use the `cupsFreeOptions` function to return the memory used when you are done with the form variables.

### cupsFormEncode

Encode options as URL-encoded form data.

char *cupsFormEncode(const char *url, size_t num_vars, cups_option_t *vars);

#### Parameters

url | URL or `NULL` for none
num_vars | Number of variables
vars | Variables

#### Return Value

URL-encoded form data

#### Discussion

This function encodes a CUPS options array as URL-encoded form data with an optional URL prefix, returning an allocated string.
Use `free` to return the memory used for the string.

### cupsFormatString

Format a UTF-8 string into a fixed size buffer.

ssize_t cupsFormatString(char *buffer, size_t bufsize, const char *format, ...);

#### Parameters

buffer | Output buffer
bufsize | Size of output buffer
format | `printf`-style format string
... | Additional arguments

#### Return Value

Number of bytes formatted

#### Discussion

This function formats a UTF-8 string into a fixed size buffer, escaping special/control characters as needed so they can be safely displayed or logged.

### cupsFormatStringv

Format a UTF-8 string into a fixed size buffer (`va_list` version).

ssize_t cupsFormatStringv(char *buffer, size_t bufsize, const char *format, va_list ap);

#### Parameters

buffer | Output buffer
bufsize | Size of output buffer
format | printf-style format string
ap | Pointer to additional arguments

#### Return Value

Number of bytes formatted

#### Discussion

This function formats a UTF-8 string into a fixed size buffer using a variable argument pointer, escaping special/control characters as needed so they can be safely displayed or logged.

### cupsFreeDestInfo

Free destination information obtained using `cupsCopyDestInfo`.

void cupsFreeDestInfo(cups_dinfo_t *dinfo);

#### Parameters

dinfo | Destination information

### cupsFreeDests

Free the memory used by the list of destinations.

void cupsFreeDests(size_t num_dests, cups_dest_t *dests);

#### Parameters

num_dests | Number of destinations
dests | Destinations

### cupsFreeJobs

Free memory used by job data.

void cupsFreeJobs(size_t num_jobs, cups_job_t *jobs);

#### Parameters

num_jobs | Number of jobs
jobs | Jobs

### cupsFreeOptions

Free all memory used by options.

void cupsFreeOptions(size_t num_options, cups_option_t *options);

#### Parameters

num_options | Number of options
options | Pointer to options

### cupsGetClock

Get a monotonic clock value in seconds.

double cupsGetClock(void);

#### Return Value

Elapsed seconds

#### Discussion

This function returns a monotonically increasing clock value in seconds. The first call will always return 0.0. Subsequent calls will return the number of seconds that have elapsed since the first call, regardless of system time changes, sleep, etc. The sub-second accuracy varies based on the operating system and hardware but is typically 10ms or better.

### cupsGetCredentialsExpiration

Return the expiration date of the credentials.

time_t cupsGetCredentialsExpiration(const char *credentials);

#### Parameters

credentials | Credentials

#### Return Value

Expiration date of credentials

### cupsGetCredentialsInfo

Return a string describing the credentials.

char *cupsGetCredentialsInfo(const char *credentials, char *buffer, size_t bufsize);

#### Parameters

credentials | Credentials
buffer | Buffer
bufsize | Size of buffer

#### Return Value

Credentials description or `NULL` on error

### cupsGetCredentialsTrust

Return the trust of credentials.

http_trust_t cupsGetCredentialsTrust(const char *path, const char *common_name, const char *credentials, bool require_ca);

#### Parameters

path | Directory path for certificate/key store or `NULL` for default
common_name | Common name for trust lookup
credentials | Credentials
require_ca | Require a CA-signed certificate?

#### Return Value

Level of trust

#### Discussion

This function determines the level of trust for the supplied credentials. The "path" parameter specifies the certificate/key store for known credentials and certificate authorities. The "common_name" parameter specifies the FQDN of the service being accessed such as "printer.example.com". The "credentials" parameter provides the credentials being evaluated, which are usually obtained with the `httpCopyPeerCredentials` function. The "require_ca" parameter specifies whether a CA-signed certificate is required for trust.
The `AllowAnyRoot`, `AllowExpiredCerts`, `TrustOnFirstUse`, and `ValidateCerts` options in the "client.conf" file (or corresponding preferences file on macOS) control the trust policy, which defaults to AllowAnyRoot=Yes, AllowExpiredCerts=No, TrustOnFirstUse=Yes, and ValidateCerts=No. When the "require_ca" parameter is `true` the AllowAnyRoot and TrustOnFirstUse policies are turned off ("No").
The returned trust value can be one of the following:

- `HTTP_TRUST_OK`: Credentials are OK/trusted
- `HTTP_TRUST_INVALID`: Credentials are invalid
- `HTTP_TRUST_EXPIRED`: Credentials are expired
- `HTTP_TRUST_RENEWED`: Credentials have been renewed
- `HTTP_TRUST_UNKNOWN`: Credentials are unknown/new

### cupsGetDefault

Get the default printer or class for the specified server.

const char *cupsGetDefault(http_t *http);

#### Parameters

http | Connection to server or `CUPS_HTTP_DEFAULT`

#### Return Value

Default printer or `NULL` for none

#### Discussion

This function returns the default printer or class as defined by the LPDEST or PRINTER environment variables. If these environment variables are not set, the server default destination is returned. Applications should use the `cupsGetDests` and `cupsGetDest` functions to get the user-defined default printer, as this function does not support the lpoptions-defined default printer.

### cupsGetDest

Get the named destination from the list.

cups_dest_t *cupsGetDest(const char *name, const char *instance, size_t num_dests, cups_dest_t *dests);

#### Parameters

name | Destination name or `NULL` for the default destination
instance | Instance name or `NULL`
num_dests | Number of destinations
dests | Destinations

#### Return Value

Destination pointer or `NULL`

#### Discussion

This function gets the named destination from the list of destinations. Use the `cupsEnumDests` or `cupsGetDests` functions to get a list of supported destinations for the current user.

### cupsGetDestMediaByIndex

Get a media name, dimension, and margins for a specific size.

bool cupsGetDestMediaByIndex(http_t *http, cups_dest_t *dest, cups_dinfo_t *dinfo, size_t n, unsigned flags, cups_media_t *media);

#### Parameters

http | Connection to destination
dest | Destination
dinfo | Destination information
n | Media size number (0-based)
flags | Media flags
media | Media

#### Return Value

`true` on success, `false` on failure

#### Discussion

The "flags" argument determines which set of media are indexed. For example, passing `CUPS_MEDIA_FLAGS_BORDERLESS` will get the Nth borderless size supported by the printer.

### cupsGetDestMediaByName

Get media names, dimensions, and margins.

bool cupsGetDestMediaByName(http_t *http, cups_dest_t *dest, cups_dinfo_t *dinfo, const char *name, unsigned flags, cups_media_t *media);

#### Parameters

http | Connection to destination
dest | Destination
dinfo | Destination information
name | Media name
flags | Media matching flags
media | Media

#### Return Value

`true` on match, `false` on failure

#### Discussion

The "media" string is a PWG media name. "Flags" provides some matching guidance (multiple flags can be combined):

- `CUPS_MEDIA_FLAGS_DEFAULT`: find the closest size supported by the printer,
- `CUPS_MEDIA_FLAGS_BORDERLESS`: find a borderless size,
- `CUPS_MEDIA_FLAGS_DUPLEX`: find a size compatible with 2-sided printing,
- `CUPS_MEDIA_FLAGS_EXACT`: find an exact match for the size, and
- `CUPS_MEDIA_FLAGS_READY`: if the printer supports media sensing, find the size amongst the "ready" media.

The matching result (if any) is returned in the `cups_size_t` structure.
Returns `true` when there is a match and `false` if there is not a match.

### cupsGetDestMediaBySize

Get media names, dimensions, and margins.

bool cupsGetDestMediaBySize(http_t *http, cups_dest_t *dest, cups_dinfo_t *dinfo, int width, int length, unsigned flags, cups_media_t *media);

#### Parameters

http | Connection to destination
dest | Destination
dinfo | Destination information
width | Media width in hundredths of millimeters
length | Media length in hundredths of millimeters
flags | Media matching flags
media | Media

#### Return Value

`true` on match, `false` on failure

#### Discussion

"Width" and "length" are the dimensions in hundredths of millimeters. "Flags" provides some matching guidance (multiple flags can be combined):

- `CUPS_MEDIA_FLAGS_DEFAULT`: find the closest size supported by the printer,
- `CUPS_MEDIA_FLAGS_BORDERLESS`: find a borderless size,
- `CUPS_MEDIA_FLAGS_DUPLEX`: find a size compatible with 2-sided printing,
- `CUPS_MEDIA_FLAGS_EXACT`: find an exact match for the size, and
- `CUPS_MEDIA_FLAGS_READY`: if the printer supports media sensing, find the size amongst the "ready" media.

The matching result (if any) is returned in the `cups_size_t` structure.
Returns `true` when there is a match and `false` if there is not a match.

### cupsGetDestMediaCount

Get the number of sizes supported by a destination.

size_t cupsGetDestMediaCount(http_t *http, cups_dest_t *dest, cups_dinfo_t *dinfo, unsigned flags);

#### Parameters

http | Connection to destination
dest | Destination
dinfo | Destination information
flags | Media flags

#### Return Value

Number of sizes

#### Discussion

The "flags" argument determines the set of media sizes that are counted. For example, passing `CUPS_MEDIA_FLAGS_BORDERLESS` will return the number of borderless sizes.

### cupsGetDestMediaDefault

Get the default size for a destination.

bool cupsGetDestMediaDefault(http_t *http, cups_dest_t *dest, cups_dinfo_t *dinfo, unsigned flags, cups_media_t *media);

#### Parameters

http | Connection to destination
dest | Destination
dinfo | Destination information
flags | Media flags
media | Media

#### Return Value

`true` on match, `false` on failure

#### Discussion

The "flags" argument determines which default size is returned. For example, passing `CUPS_MEDIA_FLAGS_BORDERLESS` will return the default borderless size, typically US Letter or A4, but sometimes 4x6 photo media.

### cupsGetDestWithURI

Get a destination associated with a URI.

cups_dest_t *cupsGetDestWithURI(const char *name, const char *uri);

#### Parameters

name | Desired printer name or `NULL`
uri | URI for the printer

#### Return Value

Destination or `NULL`

#### Discussion

"name" is the desired name for the printer. If `NULL`, a name will be created using the URI.
"uri" is the 'ipp:' or 'ipps:' URI for the printer.

### cupsGetDests

Get the list of destinations from the specified server.

size_t cupsGetDests(http_t *http, cups_dest_t **dests);

#### Parameters

http | Connection to server or `CUPS_HTTP_DEFAULT`
dests | Destinations

#### Return Value

Number of destinations

#### Discussion

Starting with CUPS 1.2, the returned list of destinations include the "printer-info", "printer-is-accepting-jobs", "printer-is-shared", "printer-make-and-model", "printer-state", "printer-state-change-time", "printer-state-reasons", "printer-type", and "printer-uri-supported" attributes as options.
CUPS 1.4 adds the "marker-change-time", "marker-colors", "marker-high-levels", "marker-levels", "marker-low-levels", "marker-message", "marker-names", "marker-types", and "printer-commands" attributes as options.
CUPS 2.2 adds accessible IPP printers to the list of destinations that can be used. The "printer-uri-supported" option will be present for those IPP printers that have been recently used.
Use the `cupsFreeDests` function to free the destination list and the `cupsGetDest` function to find a particular destination.

### cupsGetEncryption

Get the current encryption settings.

http_encryption_t cupsGetEncryption(void);

#### Return Value

Encryption settings

#### Discussion

The default encryption setting comes from the CUPS_ENCRYPTION environment variable, then the ~/.cups/client.conf file, and finally the /etc/cups/client.conf file. If not set, the default is `HTTP_ENCRYPTION_IF_REQUESTED`.
Note: The current encryption setting is tracked separately for each thread in a program. Multi-threaded programs that override the setting via the `cupsSetEncryption` function need to do so in each thread for the same setting to be used.

### cupsGetError

Return the last IPP status code received on the current thread.

ipp_status_t cupsGetError(void);

#### Return Value

IPP status code from last request

### cupsGetErrorString

Return the last IPP status-message received on the current thread.

const char *cupsGetErrorString(void);

#### Return Value

"status-message" text from last request

### cupsGetFd

Get a file from the server.

http_status_t cupsGetFd(http_t *http, const char *resource, int fd);

#### Parameters

http | Connection to server or `CUPS_HTTP_DEFAULT`
resource | Resource name
fd | File descriptor

#### Return Value

HTTP status

#### Discussion

This function returns `HTTP_STATUS_OK` when the file is successfully retrieved.

### cupsGetFile

Get a file from the server.

http_status_t cupsGetFile(http_t *http, const char *resource, const char *filename);

#### Parameters

http | Connection to server or `CUPS_HTTP_DEFAULT`
resource | Resource name
filename | Filename

#### Return Value

HTTP status

#### Discussion

This function returns `HTTP_STATUS_OK` when the file is successfully retrieved.

### cupsGetIntegerOption

Get an integer option value.

long cupsGetIntegerOption(const char *name, size_t num_options, cups_option_t *options);

#### Parameters

name | Name of option
num_options | Number of options
options | Options

#### Return Value

Option value or `LONG_MIN`

#### Discussion

`LONG_MIN` is returned when the option does not exist, is not an integer, or exceeds the range of values for the `long` type.

### cupsGetJobs

Get the jobs from the specified server.

size_t cupsGetJobs(http_t *http, cups_job_t **jobs, const char *name, bool myjobs, cups_whichjobs_t whichjobs);

#### Parameters

http | Connection to server or `CUPS_HTTP_DEFAULT`
jobs | Job data
name | `NULL` = all destinations, otherwise show jobs for named destination
myjobs | `false` = all users, `true` = mine
whichjobs | `CUPS_WHICHJOBS_ALL`, `CUPS_WHICHJOBS_ACTIVE`, or `CUPS_WHICHJOBS_COMPLETED`

#### Return Value

Number of jobs

#### Discussion

This function gets an array of jobs from the specified server.
The "name" argument specifies a destination name. The "myjobs" argument specifies whether to only show jobs for the current user (`true`) or for all users (`false`).
The "whichjobs" argument specifies which jobs to return - `CUPS_WHICHJOBS_ALL` to return all jobs regardless of state, `CUPS_WHICHJOBS_ACTIVE` to return jobs that are pending, processing, or held, and `CUPS_WHICHJOBS_COMPLETED` to return jobs that are stopped, canceled, aborted, or completed.

### cupsGetNamedDest

Get options for the named destination.

cups_dest_t *cupsGetNamedDest(http_t *http, const char *name, const char *instance);

#### Parameters

http | Connection to server or `CUPS_HTTP_DEFAULT`
name | Destination name or `NULL` for the default destination
instance | Instance name or `NULL`

#### Return Value

Destination or `NULL`

#### Discussion

This function is optimized for retrieving a single destination and should be used instead of `cupsGetDests2` and `cupsGetDest` when you either know the name of the destination or want to print to the default destination. If `NULL` is returned, the destination does not exist or there is no default destination.
If "http" is `CUPS_HTTP_DEFAULT`, the connection to the default print server will be used.
If "name" is `NULL`, the default printer for the current user will be returned.
The returned destination must be freed using `cupsFreeDests` with a "num_dests" value of 1.

### cupsGetOption

Get an option value.

const char *cupsGetOption(const char *name, size_t num_options, cups_option_t *options);

#### Parameters

name | Name of option
num_options | Number of options
options | Options

#### Return Value

Option value or `NULL`

### cupsGetPassword

Get a password from the user using the current password callback.

const char *cupsGetPassword(const char *prompt, http_t *http, const char *method, const char *resource);

#### Parameters

prompt | Prompt string
http | Connection to server or `CUPS_HTTP_DEFAULT`
method | Request method ("GET", "POST", "PUT")
resource | Resource path

#### Return Value

Password

#### Discussion

Uses the current password callback function. Returns `NULL` if the user does not provide a password.
Note: The current password callback function is tracked separately for each thread in a program. Multi-threaded programs that override the setting via the `cupsSetPasswordCB` function need to do so in each thread for the same function to be used.

### cupsGetRand

Return a 32-bit pseudo-random number.

unsigned cupsGetRand(void);

#### Return Value

Random number

#### Discussion

This function returns a 32-bit pseudo-random number suitable for use as one-time identifiers or nonces. The random numbers are generated/seeded using system entropy.

### cupsGetResponse

Get a response to an IPP request.

ipp_t *cupsGetResponse(http_t *http, const char *resource);

#### Parameters

http | Connection to server or `CUPS_HTTP_DEFAULT`
resource | HTTP resource for POST

#### Return Value

Response or `NULL` on HTTP error

#### Discussion

Use this function to get the response for an IPP request sent using `cupsSendRequest`. For requests that return additional data, use `cupsReadResponseData` after getting a successful response, otherwise call `httpFlush` to complete the response processing.

### cupsGetServer

Return the hostname/address of the current server.

const char *cupsGetServer(void);

#### Return Value

Server name

#### Discussion

The default server comes from the CUPS_SERVER environment variable, then the ~/.cups/client.conf file, and finally the /etc/cups/client.conf file. If not set, the default is the local system - either "localhost" or a domain socket path.
The returned value can be a fully-qualified hostname, a numeric IPv4 or IPv6 address, or a domain socket pathname.
Note: The current server is tracked separately for each thread in a program. Multi-threaded programs that override the server via the `cupsSetServer` function need to do so in each thread for the same server to be used.

### cupsGetUser

Return the current user's name.

const char *cupsGetUser(void);

#### Return Value

User name

#### Discussion

Note: The current user name is tracked separately for each thread in a program. Multi-threaded programs that override the user name with the `cupsSetUser` function need to do so in each thread for the same user name to be used.

### cupsGetUserAgent

Return the default HTTP User-Agent string.

const char *cupsGetUserAgent(void);

#### Return Value

User-Agent string

### cupsHMACData

Perform a HMAC function on the given data.

ssize_t cupsHMACData(const char *algorithm, const unsigned char *key, size_t keylen, const void *data, size_t datalen, unsigned char *hmac, size_t hmacsize);

#### Parameters

algorithm | Hash algorithm
key | Key
keylen | Length of key
data | Data to hash
datalen | Length of data to hash
hmac | HMAC buffer
hmacsize | Size of HMAC buffer

#### Return Value

The length of the HMAC or `-1` on error

#### Discussion

This function performs a HMAC function on the given data with the given key. The "algorithm" argument can be any of the registered, non-deprecated IPP hash algorithms for the "job-password-encryption" attribute, including "sha" for SHA-1, "sha2-256" for SHA2-256, etc.
The "hmac" argument points to a buffer of "hmacsize" bytes and should be at least 64 bytes in length for all of the supported algorithms.
The returned HMAC is binary data.

### cupsHashData

Perform a hash function on the given data.

ssize_t cupsHashData(const char *algorithm, const void *data, size_t datalen, unsigned char *hash, size_t hashsize);

#### Parameters

algorithm | Algorithm name
data | Data to hash
datalen | Length of data to hash
hash | Hash buffer
hashsize | Size of hash buffer

#### Return Value

Size of hash or -1 on error

#### Discussion

This function performs a hash function on the given data. The "algorithm" argument can be any of the registered, non-deprecated IPP hash algorithms for the "job-password-encryption" attribute, including "sha" for SHA-1, "sha2-256" for SHA2-256, etc.
The "hash" argument points to a buffer of "hashsize" bytes and should be at least 64 bytes in length for all of the supported algorithms.
The returned hash is binary data.

### cupsHashString

Format a hash value as a hexadecimal string.

const char *cupsHashString(const unsigned char *hash, size_t hashsize, char *buffer, size_t bufsize);

#### Parameters

hash | Hash
hashsize | Size of hash
buffer | String buffer
bufsize | Size of string buffer

#### Return Value

Formatted string

#### Discussion

The passed buffer must be at least 2 * hashsize + 1 characters in length.

### cupsJSONAdd

Add a node to a JSON node.

void cupsJSONAdd(cups_json_t *parent, cups_json_t *after, cups_json_t *node);

#### Parameters

parent | Parent JSON node
after | Previous sibling node or `NULL` to append to the end
node | JSON node to add

#### Discussion

This function adds an existing JSON node as a child of other JSON node. The "parent" argument specifies the node to add to. The "after" argument specifies a child of the parent node or `NULL` to append to the end of the children.
Note: The node being added must not already be the child of another parent.

### cupsJSONDelete

Delete a JSON node and all of its children.

void cupsJSONDelete(cups_json_t *json);

#### Parameters

json | JSON node

### cupsJSONExportFile

Save a JSON node tree to a file.

bool cupsJSONExportFile(cups_json_t *json, const char *filename);

#### Parameters

json | JSON root node
filename | JSON filename

#### Return Value

`true` on success, `false` on failure

### cupsJSONExportString

Save a JSON node tree to a string.

char *cupsJSONExportString(cups_json_t *json);

#### Parameters

json | JSON root node

#### Return Value

JSON string or `NULL` on error

#### Discussion

This function saves a JSON node tree to an allocated string. The resulting string must be freed using the `free` function.

### cupsJSONFind

Find the value(s) associated with a given key.

cups_json_t *cupsJSONFind(cups_json_t *json, const char *key);

#### Parameters

json | JSON object node
key | Object key

#### Return Value

JSON value or `NULL`

### cupsJSONGetChild

Get the first child node of an array or object node.

cups_json_t *cupsJSONGetChild(cups_json_t *json, size_t n);

#### Parameters

json | JSON array or object node
n | Child node number (starting at `0`)

#### Return Value

First child node or `NULL`

### cupsJSONGetCount

Get the number of child nodes.

size_t cupsJSONGetCount(cups_json_t *json);

#### Parameters

json | JSON array or object node

#### Return Value

Number of child nodes

### cupsJSONGetKey

Get the key string, if any.

const char *cupsJSONGetKey(cups_json_t *json);

#### Parameters

json | JSON string node

#### Return Value

String value

#### Discussion

This function returns the key string for a JSON key node or `NULL` if the node is not a key.

### cupsJSONGetNumber

Get the number value, if any.

double cupsJSONGetNumber(cups_json_t *json);

#### Parameters

json | JSON number node

#### Return Value

Number value

#### Discussion

This function returns the number value for a JSON number node or `0.0` if the node is not a number.

### cupsJSONGetParent

Get the parent node, if any.

cups_json_t *cupsJSONGetParent(cups_json_t *json);

#### Parameters

json | JSON node

#### Return Value

Parent node or `NULL` if none

### cupsJSONGetSibling

Get the next sibling node, if any.

cups_json_t *cupsJSONGetSibling(cups_json_t *json);

#### Parameters

json | JSON node

#### Return Value

Sibling node or `NULL` if none

### cupsJSONGetString

Get the string value, if any.

const char *cupsJSONGetString(cups_json_t *json);

#### Parameters

json | JSON string node

#### Return Value

String value

#### Discussion

This function returns the string value for a JSON string node or `NULL` if the node is not a string.

### cupsJSONGetType

Get the type of a JSON node.

cups_jtype_t cupsJSONGetType(cups_json_t *json);

#### Parameters

json | JSON node

#### Return Value

JSON node type

### cupsJSONImportFile

Load a JSON object file.

cups_json_t *cupsJSONImportFile(const char *filename);

#### Parameters

filename | JSON filename

#### Return Value

Root JSON object node

### cupsJSONImportString

Load a JSON object from a string.

cups_json_t *cupsJSONImportString(const char *s);

#### Parameters

s | JSON string

#### Return Value

Root JSON object node

### cupsJSONImportURL

Load a JSON object from a URL.

cups_json_t *cupsJSONImportURL(const char *url, time_t *last_modified);

#### Parameters

url | URL
last_modified | Last modified date/time or `NULL`

#### Return Value

Root JSON object node

#### Discussion

This function loads a JSON object from a URL. The "url" can be a "http:" or "https:" URL. The "last_modified" argument provides a pointer to a `time_t` variable with the last modified date and time from a previous load. If `NULL` or the variable has a value of 0, the JSON is loaded unconditionally from the URL.
On success, a pointer to the root JSON object node is returned and the "last_modified" variable, if not `NULL`, is updated to the Last-Modified date and time returned by the server. Otherwise, `NULL` is returned with the `cupsGetError` value set to `IPP_STATUS_OK_EVENTS_COMPLETE` if the JSON data has not been updated since the "last_modified" date and time or a suitable `IPP_STATUS_ERROR_` value if an error occurred.

### cupsJSONNew

Create a new JSON node.

cups_json_t *cupsJSONNew(cups_json_t *parent, cups_json_t *after, cups_jtype_t type);

#### Parameters

parent | Parent JSON node or `NULL` for a root node
after | Previous sibling node or `NULL` to append to the end
type | JSON node type

#### Return Value

JSON node

### cupsJSONNewKey

Create a new JSON key node.

cups_json_t *cupsJSONNewKey(cups_json_t *parent, cups_json_t *after, const char *key);

#### Parameters

parent | Parent JSON node or `NULL` for a root node
after | Previous sibling node or `NULL` to append to the end
key | Key string

#### Return Value

JSON node

### cupsJSONNewNumber

Create a new JSON number node.

cups_json_t *cupsJSONNewNumber(cups_json_t *parent, cups_json_t *after, double value);

#### Parameters

parent | Parent JSON node or `NULL` for a root node
after | Previous sibling node or `NULL` to append to the end
value | Number value

#### Return Value

JSON node

### cupsJSONNewString

Create a new JSON string node.

cups_json_t *cupsJSONNewString(cups_json_t *parent, cups_json_t *after, const char *value);

#### Parameters

parent | Parent JSON node or `NULL` for a root node
after | Previous sibling node or `NULL` to append to the end
value | String value

#### Return Value

JSON node

### cupsJWTDelete

Free the memory used for a JSON Web Token.

void cupsJWTDelete(cups_jwt_t *jwt);

#### Parameters

jwt | JWT object

### cupsJWTExportString

Export a JWT with the JWS Compact or JWS JSON (Flattened) Serialization format.

char *cupsJWTExportString(cups_jwt_t *jwt, cups_jws_format_t format);

#### Parameters

jwt | JWT object
format | JWS serialization format

#### Return Value

JWT/JWS Serialization string

#### Discussion

This function exports a JWT to a JWS Compact or JWS JSON Serialization string. The JSON output is always the "flattened" format since the JWT only contains a single signature.
The return value must be freed using the `free` function.

### cupsJWTGetAlgorithm

Get the signature algorithm used by a JSON Web Token.

cups_jwa_t cupsJWTGetAlgorithm(cups_jwt_t *jwt);

#### Parameters

jwt | JWT object

#### Return Value

Signature algorithm

### cupsJWTGetClaimNumber

Get the number value of a claim.

double cupsJWTGetClaimNumber(cups_jwt_t *jwt, const char *claim);

#### Parameters

jwt | JWT object
claim | Claim name

#### Return Value

Number value

### cupsJWTGetClaimString

Get the string value of a claim.

const char *cupsJWTGetClaimString(cups_jwt_t *jwt, const char *claim);

#### Parameters

jwt | JWT object
claim | Claim name

#### Return Value

String value

### cupsJWTGetClaimType

Get the value type of a claim.

cups_jtype_t cupsJWTGetClaimType(cups_jwt_t *jwt, const char *claim);

#### Parameters

jwt | JWT object
claim | Claim name

#### Return Value

JSON value type

### cupsJWTGetClaimValue

Get the value node of a claim.

cups_json_t *cupsJWTGetClaimValue(cups_jwt_t *jwt, const char *claim);

#### Parameters

jwt | JWT object
claim | Claim name

#### Return Value

JSON value node

### cupsJWTGetClaims

Get the JWT claims as a JSON object.

cups_json_t *cupsJWTGetClaims(cups_jwt_t *jwt);

#### Parameters

jwt | JWT object

#### Return Value

JSON object

### cupsJWTGetHeaderNumber

Get the number value of a protected header.

double cupsJWTGetHeaderNumber(cups_jwt_t *jwt, const char *header);

#### Parameters

jwt | JWT object
header | Header name

#### Return Value

Number value

### cupsJWTGetHeaderString

Get the string value of a protected header.

const char *cupsJWTGetHeaderString(cups_jwt_t *jwt, const char *header);

#### Parameters

jwt | JWT object
header | Header name

#### Return Value

String value

### cupsJWTGetHeaderType

Get the value type of a protected header.

cups_jtype_t cupsJWTGetHeaderType(cups_jwt_t *jwt, const char *header);

#### Parameters

jwt | JWT object
header | Header name

#### Return Value

JSON value type

### cupsJWTGetHeaderValue

Get the value node of a protected header.

cups_json_t *cupsJWTGetHeaderValue(cups_jwt_t *jwt, const char *header);

#### Parameters

jwt | JWT object
header | Header name

#### Return Value

JSON value node

### cupsJWTGetHeaders

Get the JWT protected headers as a JSON object.

cups_json_t *cupsJWTGetHeaders(cups_jwt_t *jwt);

#### Parameters

jwt | JWT object

#### Return Value

JSON object

### cupsJWTHasValidSignature

Determine whether the JWT has a valid signature.

bool cupsJWTHasValidSignature(cups_jwt_t *jwt, cups_json_t *jwk);

#### Parameters

jwt | JWT object
jwk | JWK key set

#### Return Value

`true` if value, `false` otherwise

### cupsJWTImportString

Import a JSON Web Token or JSON Web Signature.

cups_jwt_t *cupsJWTImportString(const char *s, cups_jws_format_t format);

#### Parameters

s | JWS string
format | JWS serialization format

#### Return Value

JWT object

### cupsJWTLoadCredentials

Load X.509 credentials and private key into a JSON Web Key for signing.

cups_json_t *cupsJWTLoadCredentials(const char *path, const char *common_name);

#### Parameters

path | Directory path for certificate/key store or `NULL` for default
common_name | Common name

#### Return Value

JSON Web Key of `NULL` on error

### cupsJWTMakePrivateKey

Make a JSON Web Key for encryption and signing.

cups_json_t *cupsJWTMakePrivateKey(cups_jwa_t alg);

#### Parameters

alg | Signing/encryption algorithm

#### Return Value

Private JSON Web Key or `NULL` on error

#### Discussion

This function makes a JSON Web Key (JWK) for the specified JWS/JWE algorithm for use when signing or encrypting JSON Web Tokens. The resulting JWK must not be provided to clients - instead, call `cupsJWTMakePublicKey` to produce a public key subset suitable for verification and decryption.

### cupsJWTMakePublicKey

Make a JSON Web Key for decryption and verification.

cups_json_t *cupsJWTMakePublicKey(cups_json_t *jwk);

#### Parameters

jwk | Private JSON Web Key

#### Return Value

Public JSON Web Key or `NULL` on error

#### Discussion

This function makes a public JSON Web Key (JWK) from the specified private JWK suitable for use when decrypting or verifying a JWE/JWS message.

### cupsJWTNew

Create a new, empty JSON Web Token.

cups_jwt_t *cupsJWTNew(const char *type, cups_json_t *claims);

#### Parameters

type | JWT type or `NULL` for default ("JWT")
claims | JSON claims or `NULL` for empty

#### Return Value

JWT object

### cupsJWTSetClaimNumber

Set a claim number.

void cupsJWTSetClaimNumber(cups_jwt_t *jwt, const char *claim, double value);

#### Parameters

jwt | JWT object
claim | Claim name
value | Number value

### cupsJWTSetClaimString

Set a claim string.

void cupsJWTSetClaimString(cups_jwt_t *jwt, const char *claim, const char *value);

#### Parameters

jwt | JWT object
claim | Claim name
value | String value

### cupsJWTSetClaimValue

Set a claim value.

void cupsJWTSetClaimValue(cups_jwt_t *jwt, const char *claim, cups_json_t *value);

#### Parameters

jwt | JWT object
claim | Claim name
value | JSON value node

### cupsJWTSetHeaderNumber

Set a protected header number.

void cupsJWTSetHeaderNumber(cups_jwt_t *jwt, const char *header, double value);

#### Parameters

jwt | JWT object
header | Header name
value | Number value

### cupsJWTSetHeaderString

Set a protected header string.

void cupsJWTSetHeaderString(cups_jwt_t *jwt, const char *header, const char *value);

#### Parameters

jwt | JWT object
header | Header name
value | String value

### cupsJWTSetHeaderValue

Set a protected header value.

void cupsJWTSetHeaderValue(cups_jwt_t *jwt, const char *header, cups_json_t *value);

#### Parameters

jwt | JWT object
header | Header name
value | JSON value node

### cupsJWTSign

Sign a JSON Web Token, creating a JSON Web Signature.

bool cupsJWTSign(cups_jwt_t *jwt, cups_jwa_t alg, cups_json_t *jwk);

#### Parameters

jwt | JWT object
alg | Signing algorithm
jwk | JWK key set

#### Return Value

`true` on success, `false` on error

### cupsLangAddStrings

Add strings for the specified language.

bool cupsLangAddStrings(const char *language, const char *strings);

#### Parameters

language | Language name
strings | Contents of ".strings" file

#### Return Value

`true` on success, `false` on failure

#### Discussion

This function adds strings for the specified language. It is equivalent to calling `cupsLangFind` followed by `cupsLangLoadStrings`.

### cupsLangDefault

Return the default language.

cups_lang_t *cupsLangDefault(void);

#### Return Value

Language data

### cupsLangFind

Find a language localization.

cups_lang_t *cupsLangFind(const char *language);

#### Parameters

language | Language or locale name, `NULL` for the current locale

#### Return Value

Language data

#### Discussion

This function finds the localization information for the specified language or locale name.

### cupsLangFormatString

Create a localized formatted string.

const char *cupsLangFormatString(cups_lang_t *lang, char *buffer, size_t bufsize, const char *format, ...);

#### Parameters

lang | Language data
buffer | Output buffer
bufsize | Size of output buffer
format | Printf-style format string
... | Additional arguments

#### Return Value

Formatted string

#### Discussion

This function formats a string using the localized version of the "format" string argument, which supports all of the `printf` format specifiers.

### cupsLangGetEncoding

Get the default encoding for the current locale.

cups_encoding_t cupsLangGetEncoding(void);

#### Return Value

Character encoding

### cupsLangGetName

Get the language name.

const char *cupsLangGetName(cups_lang_t *lang);

#### Parameters

lang | Language data

#### Return Value

Language name

### cupsLangGetString

Get a localized message string.

const char *cupsLangGetString(cups_lang_t *lang, const char *message);

#### Parameters

lang | Language
message | Message

#### Return Value

Localized message

#### Discussion

This function gets a localized UTF-8 message string for the specified language. If the message is not localized, the original message pointer is returned.

### cupsLangIsRTL

Get the writing direction.

bool cupsLangIsRTL(cups_lang_t *lang);

#### Parameters

lang | Language

#### Return Value

`true` if right-to-left, `false` if left-to-right

#### Discussion

This function gets the writing direction for the specified language.

### cupsLangLoadStrings

Load a message catalog for a language.

bool cupsLangLoadStrings(cups_lang_t *lang, const char *filename, const char *strings);

#### Parameters

lang | Language data
filename | Filename or `NULL` for none
strings | Strings or `NULL` for none

#### Return Value

`true` on success, `false` on failure

#### Discussion

This function loads a message catalog for a language. The catalog must be in the Apple .strings format. For example, the following translates the strings "Yes", "No", and "Welcome, %s." to French:

    "Yes" = "Oui";
    "No" = "Non";
    "Welcome, %s." = "Bievenue, %s.";

### cupsLangPrintf

Print a formatted message string to a file.

ssize_t cupsLangPrintf(FILE *fp, const char *format, ...);

#### Parameters

fp | File to write to
format | Message string to use
... | Additional arguments as needed

#### Return Value

Number of bytes written

### cupsLangPuts

Print a static message string to a file.

ssize_t cupsLangPuts(FILE *fp, const char *message);

#### Parameters

fp | File to write to
message | Message string to use

#### Return Value

Number of bytes written

### cupsLangSetDirectory

Set the directory containing localizations.

void cupsLangSetDirectory(const char *d);

#### Parameters

d | Directory name

#### Discussion

This function sets the directory where .strings files can be found. The files are named "LOCALE.string" where "LOCALE" is the locale name, for example "fr" for generic French and "fr-CA" for Canadian French.

### cupsLangSetLocale

Set the current locale and transcode the command-line.

void cupsLangSetLocale(char *argv[]);

#### Parameters

argv[] | Command-line arguments

### cupsLocalizeDestMedia

Get the localized string for a destination media size.

const char *cupsLocalizeDestMedia(http_t *http, cups_dest_t *dest, cups_dinfo_t *dinfo, unsigned flags, cups_media_t *media);

#### Parameters

http | Connection to destination
dest | Destination
dinfo | Destination information
flags | Media flags
media | Media info

#### Return Value

Localized string

#### Discussion

The returned string is stored in the destination information and will become invalid if the destination information is deleted.

### cupsLocalizeDestOption

Get the localized string for a destination option.

const char *cupsLocalizeDestOption(http_t *http, cups_dest_t *dest, cups_dinfo_t *dinfo, const char *option);

#### Parameters

http | Connection to destination
dest | Destination
dinfo | Destination information
option | Option to localize

#### Return Value

Localized string

#### Discussion

The returned string is stored in the destination information and will become invalid if the destination information is deleted.

### cupsLocalizeDestValue

Get the localized string for a destination option+value pair.

const char *cupsLocalizeDestValue(http_t *http, cups_dest_t *dest, cups_dinfo_t *dinfo, const char *option, const char *value);

#### Parameters

http | Connection to destination
dest | Destination
dinfo | Destination information
option | Option to localize
value | Value to localize

#### Return Value

Localized string

#### Discussion

The returned string is stored in the destination information and will become invalid if the destination information is deleted.

### cupsLocalizeNotifySubject

Return the localized subject for the given notification message.

char *cupsLocalizeNotifySubject(cups_lang_t *lang, ipp_t *event);

#### Parameters

lang | Language data
event | Event data

#### Return Value

Subject string or `NULL`

#### Discussion

This function returns a localized subject string for the given notification message. The returned string must be freed by the caller using `free`.

### cupsLocalizeNotifyText

Return the localized text for the given notification message.

char *cupsLocalizeNotifyText(cups_lang_t *lang, ipp_t *event);

#### Parameters

lang | Language data
event | Event data

#### Return Value

Message text or `NULL`

#### Discussion

This function returns a localized text string for the given notification message. The returned string must be freed by the caller using `free`.

### cupsMutexDestroy

Destroy a mutex.

void cupsMutexDestroy(cups_mutex_t *mutex);

#### Parameters

mutex | Mutex

### cupsMutexInit

Initialize a mutex.

void cupsMutexInit(cups_mutex_t *mutex);

#### Parameters

mutex | Mutex

### cupsMutexLock

Lock a mutex.

void cupsMutexLock(cups_mutex_t *mutex);

#### Parameters

mutex | Mutex

### cupsMutexUnlock

Unlock a mutex.

void cupsMutexUnlock(cups_mutex_t *mutex);

#### Parameters

mutex | Mutex

### cupsOAuthClearTokens

Clear any cached authorization information.

void cupsOAuthClearTokens(const char *auth_uri, const char *resource_uri);

#### Parameters

auth_uri | Authorization server URI
resource_uri | Resource server URI

#### Discussion

This function clears cached authorization information for the given Authorization Server "auth_uri" and Resource "resource_uri" combination.

### cupsOAuthCopyAccessToken

Get a cached access token.

char *cupsOAuthCopyAccessToken(const char *auth_uri, const char *resource_uri, time_t *access_expires);

#### Parameters

auth_uri | Authorization Server URI
resource_uri | Resource URI
access_expires | Access expiration time or `NULL` for don't care

#### Return Value

Access token

#### Discussion

This function makes a copy of a cached access token and any associated expiration time for the given Authorization Server "auth_uri" and Resource "resource_uri" combination. The returned access token must be freed using the `free` function.
`NULL` is returned if no token is cached.

### cupsOAuthCopyClientId

Get the cached `client_id` value.

char *cupsOAuthCopyClientId(const char *auth_uri, const char *redirect_uri);

#### Parameters

auth_uri | Authorization Server URI
redirect_uri | Redirection URI

#### Return Value

`client_id` value

#### Discussion

This function makes a copy of the cached `client_id` value for a given Authorization Server "auth_uri" and Redirection URI "resource_uri". The returned value must be freed using the `free` function.
`NULL` is returned if no `client_id` is cached.

### cupsOAuthCopyRefreshToken

Get a cached refresh token.

char *cupsOAuthCopyRefreshToken(const char *auth_uri, const char *resource_uri);

#### Parameters

auth_uri | Authorization Server URI
resource_uri | Resource URI

#### Return Value

Refresh token

#### Discussion

This function makes a copy of a cached refresh token for the given given Authorization Server "auth_uri" and Resource "resource_uri" combination. The returned refresh token must be freed using the `free` function.
`NULL` is returned if no refresh token is cached.

### cupsOAuthCopyUserId

Get cached user identification information.

cups_jwt_t *cupsOAuthCopyUserId(const char *auth_uri, const char *resource_uri);

#### Parameters

auth_uri | Authorization Server URI
resource_uri | Resource URI

#### Return Value

Identification information

#### Discussion

This function makes a copy of cached user identification information for the given Authorization Server "auth_uri" and Resource "resource_uri" combination. The returned user information must be freed using the `cupsJWTDelete` function.
`NULL` is returned if no identification information is cached.

### cupsOAuthGetAuthorizationCode

Authorize access using a web browser.

char *cupsOAuthGetAuthorizationCode(const char *auth_uri, cups_json_t *metadata, const char *resource_uri, const char *scopes, const char *redirect_uri);

#### Parameters

auth_uri | Authorization Server URI
metadata | Authorization Server metadata
resource_uri | Resource URI
scopes | Space-delimited scopes
redirect_uri | Redirect URI or `NULL` for default

#### Return Value

Authorization code or `NULL` on error

#### Discussion

This function performs a local/"native" OAuth authorization flow to obtain an authorization code for use with the `cupsOAuthGetTokens` function.
The "auth_uri" argument specifies the URI for the OAuth Authorization Server. The "metadata" argument specifies the Authorization Server metadata as obtained using `cupsOAuthCopyMetadata` and/or `cupsOAuthGetMetadata`.
The "resource_uri" argument specifies the URI for a resource (printer, web file, etc.) that you which to access.
The "scopes" argument specifies zero or more whitespace-delimited scope names to request during authorization. The list of supported scope names are available from the Authorization Server metadata, for example:

    cups_json_t *metadata = cupsOAuthGetMetadata(auth_uri);
    cups_json_t *scopes_supported = cupsJSONFind(metadata, "scopes_supported");

The "redirect_uri" argument specifies a 'http:' URL with a listen address, port, and path to use. If `NULL`, 127.0.0.1 on a random port is used with a path of "/".
The returned authorization code must be freed using the `free` function.

### cupsOAuthGetClientId

Register a client application and get its ID.

char *cupsOAuthGetClientId(const char *auth_uri, cups_json_t *metadata, const char *redirect_uri, const char *logo_uri, const char *tos_uri);

#### Parameters

auth_uri | Authorization Server URI
metadata | Authorization Server metadata
redirect_uri | Redirection URL
logo_uri | Logo URL or `NULL` for none
tos_uri | Terms-of-service URL or `NULL` for none

#### Return Value

`client_id` string or `NULL` on error

#### Discussion

This function registers a client application with the specified OAuth Authorization Server.
The "auth_uri" argument specifies the URI for the OAuth Authorization Server. The "metadata" argument specifies the Authorization Server metadata as obtained using `cupsOAuthCopyMetadata` and/or `cupsOAuthGetMetadata`.
The "redirect_uri" argument specifies the URL to use for providing authorization results to a WWW application.
The "logo_uri" argument specifies a public URL for the logo of your application, while the "tos_uri" specifies a public URL for the terms of service for your application.
The returned "client_id" string must be freed using the `free` function.
Note: This function should only be used to register WWW applications. The `cupsOAuthGetAuthorizationCode` function handles registration of local/"native" applications for you.

### cupsOAuthGetDeviceGrant

Get a device authorization grant for the specified resource and scope(s).

cups_json_t *cupsOAuthGetDeviceGrant(const char *auth_uri, cups_json_t *metadata, const char *resource_uri, const char *scopes);

#### Parameters

auth_uri | Authorization Server URI
metadata | Authorization Server metadata
resource_uri | Resource URI
scopes | Space-delimited scopes

#### Return Value

Grant data or `NULL` on error

#### Discussion

This function requests a device authorization grant for the specified resource and scope(s). Device authorization grants allow a user to open a web page on any device to authorize access to the resource.
The "auth_uri" argument specifies the URI for the OAuth Authorization Server. The "metadata" argument specifies the Authorization Server metadata as obtained using `cupsOAuthCopyMetadata` and/or `cupsOAuthGetMetadata`.
The "resource_uri" argument specifies the URI for a resource (printer, web file, etc.) that you which to access.
The "scopes" argument specifies zero or more whitespace-delimited scope names to request during authorization. The list of supported scope names are available from the Authorization Server metadata, for example:

    cups_json_t *metadata = cupsOAuthGetMetadata(auth_uri);
    cups_json_t *scopes_supported = cupsJSONFind(metadata, "scopes_supported");

The returned JSON object must be freed using the `cupsJSONDelete` function and contains the following information:

- `CUPS_ODEVGRANT_DEVICE_CODE`: The device code string to be used in subsequent `cupsOAuthGetTokens` calls.
- `CUPS_ODEVGRANT_EXPIRES_IN`: The expiration date/time as a number of seconds since the Unix epoch.
- `CUPS_ODEVGRANT_INTERVAL`: The number of seconds to wait between calls to `cupsOAuthGetTokens`.
- `CUPS_ODEVGRANT_USER_CODE`: The user code to enter on the verification web page.
- `CUPS_ODEVGRANT_VERIFICATION_URL`: The URL for the verification web page.
- `CUPS_ODEVGRANT_VERIFICATION_URL_COMPLETE`: The URL for the verification web page with the user code filled in.

The values can be obtained using the `cupsJSONFind`, `cupsJSONGetNumber`, and `cupsJSONGetString` functions, for example:

    cups_json_t *grant = cupsOAuthGetDeviceGrant(...);

    const char *verification_url = cupsJSONGetString(cupsJSONFind(grant, CUPS_ODEVGRANT_VERIFICATION_URL));
    double interval = cupsJSONGetNumber(cupsJSONFind(grant, CUPS_ODEVGRANT_INTERVAL));

### cupsOAuthGetJWKS

Get the JWT key set for an Authorization Server.

cups_json_t *cupsOAuthGetJWKS(const char *auth_uri, cups_json_t *metadata);

#### Parameters

auth_uri | Authorization server URI
metadata | Server metadata

#### Return Value

JWKS or `NULL` on error

#### Discussion

This function gets the JWT key set for the specified Authorization Server "auth_uri". The "metadata" value is obtained using the `cupsOAuthGetMetadata` function. The returned key set is cached per-user for better performance and must be freed using the `cupsJSONDelete` function.
The key set is typically used to validate JWT bearer tokens using the `cupsJWTHasValidSignature` function.

### cupsOAuthGetMetadata

Get the metadata for an Authorization Server.

cups_json_t *cupsOAuthGetMetadata(const char *auth_uri);

#### Parameters

auth_uri | Authorization Server URI

#### Return Value

JSON metadata or `NULL` on error

#### Discussion

This function gets the RFC 8414 or Open ID Connect metadata for the specified OAuth Authorization Server URI "auth_uri".
The returned metadata is cached per-user for better performance and must be freed using the `cupsJSONDelete` function.

### cupsOAuthGetTokens

Obtain access and refresh tokens.

char *cupsOAuthGetTokens(const char *auth_uri, cups_json_t *metadata, const char *resource_uri, const char *grant_code, cups_ogrant_t grant_type, const char *redirect_uri, time_t *access_expires);

#### Parameters

auth_uri | Authorization Server URI
metadata | Authorization Server metadata
resource_uri | Resource URI
grant_code | Authorization code, device code, or refresh token
grant_type | Grant code type
redirect_uri | Redirect URI or `NULL` for device grants
access_expires | Expiration time for access token

#### Return Value

Access token or `NULL` on error

#### Discussion

This function obtains a access and refresh tokens from an OAuth Authorization Server. OpenID Authorization Servers also provide user identification information.
The "auth_uri" argument specifies the URI for the OAuth Authorization Server. The "metadata" argument specifies the Authorization Server metadata as obtained using `cupsOAuthCopyMetadata` and/or `cupsOAuthGetMetadata`.
The "resource_uri" argument specifies the URI for a resource (printer, web file, etc.) that you which to access.
The "grant_code" argument specifies the code or token to use while the "grant_type" argument specifies the type of code:

- `CUPS_OGRANT_AUTHORIZATION_CODE`: A user authorization grant code.
- `CUPS_OGRANT_DEVICE_CODE`: A device authorization grant code.
- `CUPS_OGRANT_REFRESH_TOKEN`: A refresh token.

The "redirect_uri" specifies the redirection URI used to obtain the code. The constant `CUPS_OAUTH_REDIRECT_URI` should be used for codes obtained using the `cupsOAuthGetAuthorizationCode` function.
When successful, the access token and expiration time are returned. The access token must be freed using the `free` function. The new refresh token and any user ID information can be obtained using the `cupsOAuthCopyRefreshToken` and `cupsOAuthCopyUserId` functions respectively.
When authorizing using a device code (`CUPS_OGRANT_DEVICE_CODE`) and a device access token is not yet ready, a `NULL` access token is returned with the expiration time set to the next recommended query time. If the "access_expires" value is set to `0` then the device authorization failed.

### CUPS 2.5 cupsOAuthGetUserId

Get the user ID token associated with the given access token.

cups_jwt_t *cupsOAuthGetUserId(const char *auth_uri, cups_json_t *metadata, const char *access_token);

#### Parameters

auth_uri | Authorization Server URL
metadata | Authorization Server metadata
access_token | Access (Bearer) token

#### Return Value

Identification information or `NULL` if none

#### Discussion

This function retrieves the user ID token associated with a given access token. The user ID information is cached until the token expires to minimize the overhead of communicating with the Authorization Server.

### cupsOAuthMakeAuthorizationURL

Make an authorization URL.

char *cupsOAuthMakeAuthorizationURL(const char *auth_uri, cups_json_t *metadata, const char *resource_uri, const char *scopes, const char *client_id, const char *code_verifier, const char *nonce, const char *redirect_uri, const char *state);

#### Parameters

auth_uri | Authorization Server URI
metadata | Authorization Server metadata
resource_uri | Resource URI
scopes | Space-delimited scope(s)
client_id | Client ID
code_verifier | Code verifier string
nonce | Nonce
redirect_uri | Redirection URI
state | State

#### Return Value

Authorization URL

#### Discussion

This function makes an authorization URL for the specified authorization server and resource.
The "auth_uri" argument specifies the URI for the OAuth Authorization Server. The "metadata" argument specifies the Authorization Server metadata as obtained using `cupsOAuthCopyMetadata` and/or `cupsOAuthGetMetadata`.
The "resource_uri" argument specifies the URI for a resource (printer, web file, etc.) that you which to access.
The "scopes" argument specifies zero or more whitespace-delimited scope names to request during authorization. The list of supported scope names are available from the Authorization Server metadata, for example:

    cups_json_t *metadata = cupsOAuthGetMetadata(auth_uri);
    cups_json_t *scopes_supported = cupsJSONFind(metadata, "scopes_supported");

The "client_id" argument specifies the client identifier obtained using `cupsOAuthCopyClientId` and/or `cupsOAuthGetClientId`.
The "client_id" argument is the string returned by `cupsOAuthCopyClientId` or `cupsOAuthGetClientId`.
The "code_verifier" argument specifies a random Base64URL-encoded string that is used by the Proof Key for Code Exchange [RFC7636] extension to help secure the authorization flow. The `cupsOAuthMakeBase64Random` function can be used to generate this string.
The "nonce" argument specifies a random Base64URL-encoded string that is used by OpenID to validate the ID token. The `cupsOAuthMakeBase64Random` function can be used to generate this string.
The "redirect_uri" argument specifies the URI that will receive the authorization grant code.
The "state" argument is a unique (random) identifier for the authorization request. It is provided to the redirection URI as a form parameter.

### cupsOAuthMakeBase64Random

Make a random data string.

char *cupsOAuthMakeBase64Random(size_t len);

#### Parameters

len | Number of bytes

#### Return Value

Random string

#### Discussion

This function creates a string containing random data that has been Base64URL encoded. "len" specifies the number of random bytes to include in the string. The returned string must be freed using the `free` function.

### cupsOAuthSaveClientData

Save client_id and client_secret values.

void cupsOAuthSaveClientData(const char *auth_uri, const char *redirect_uri, const char *client_id, const char *client_secret);

#### Parameters

auth_uri | Authorization Server URI
redirect_uri | Redirection URI
client_id | client_id or `NULL` to delete
client_secret | client_secret value or `NULL` for none

#### Discussion

This function saves the "client_id" and "client_secret" values for the given Authorization Server "auth_uri" and redirection URI "redirect_uri". If the "client_id" is `NULL` then any saved values are deleted from the per-user store.

### cupsOAuthSaveTokens

Save authorization and refresh tokens.

void cupsOAuthSaveTokens(const char *auth_uri, const char *resource_uri, const char *access_token, time_t access_expires, const char *user_id, const char *refresh_token);

#### Parameters

auth_uri | Authorization Server URI
resource_uri | Resource URI
access_token | Access token or `NULL` to delete
access_expires | Access expiration time
user_id | User ID or `NULL` to delete
refresh_token | Refresh token or `NULL` to delete

#### Discussion

This function saves the access token "access_token", user ID "user_id", and refresh token "refresh_token" values for the given Authorization Server "auth_uri" and resource "resource_uri". Specifying `NULL` for any of the values will delete the corresponding saved values from the per-user store.

### cupsParseOptions

Parse options from a command-line argument.

size_t cupsParseOptions(const char *arg, const char **end, size_t num_options, cups_option_t **options);

#### Parameters

arg | Argument to parse
end | Pointer to end of options or `NULL` for "don't care"
num_options | Number of options
options | Options found

#### Return Value

Number of options found

#### Discussion

This function converts space-delimited name/value pairs according to the PAPI text option ABNF specification. Collection values ("name={a=... b=... c=...}") are stored with the curley brackets intact - use `cupsParseOptions` on the value to extract the collection attributes.
The "end" argument, if not `NULL`, receives a pointer to the end of the options.

### cupsPutFd

Put a file on the server.

http_status_t cupsPutFd(http_t *http, const char *resource, int fd);

#### Parameters

http | Connection to server or `CUPS_HTTP_DEFAULT`
resource | Resource name
fd | File descriptor

#### Return Value

HTTP status

#### Discussion

This function returns `HTTP_STATUS_CREATED` when the file is stored successfully.

### cupsPutFile

Put a file on the server.

http_status_t cupsPutFile(http_t *http, const char *resource, const char *filename);

#### Parameters

http | Connection to server or `CUPS_HTTP_DEFAULT`
resource | Resource name
filename | Filename

#### Return Value

HTTP status

#### Discussion

This function returns `HTTP_CREATED` when the file is stored successfully.

### cupsRWDestroy

Destroy a reader/writer lock.

void cupsRWDestroy(cups_rwlock_t *rwlock);

#### Parameters

rwlock | Reader/writer lock

### cupsRWInit

Initialize a reader/writer lock.

void cupsRWInit(cups_rwlock_t *rwlock);

#### Parameters

rwlock | Reader/writer lock

### cupsRWLockRead

Acquire a reader/writer lock for reading.

void cupsRWLockRead(cups_rwlock_t *rwlock);

#### Parameters

rwlock | Reader/writer lock

### cupsRWLockWrite

Acquire a reader/writer lock for writing.

void cupsRWLockWrite(cups_rwlock_t *rwlock);

#### Parameters

rwlock | Reader/writer lock

### cupsRWUnlock

Release a reader/writer lock.

void cupsRWUnlock(cups_rwlock_t *rwlock);

#### Parameters

rwlock | Reader/writer lock

### cupsRasterClose

Close a raster stream.

void cupsRasterClose(cups_raster_t *r);

#### Parameters

r | Stream to free

#### Discussion

The file descriptor associated with the raster stream must be closed separately as needed.

### cupsRasterGetErrorString

Return the last error from a raster function.

const char *cupsRasterGetErrorString(void);

#### Return Value

Last error

#### Discussion

If there are no recent errors, `NULL` is returned.

### cupsRasterInitHeader

Initialize a page header for PWG Raster output.

bool cupsRasterInitHeader(cups_page_header_t *h, cups_media_t *media, const char *optimize, ipp_quality_t quality, const char *intent, ipp_orient_t orientation, const char *sides, const char *type, int xdpi, int ydpi, const char *sheet_back);

#### Parameters

h | Page header
media | Media information
optimize | IPP "print-content-optimize" value
quality | IPP "print-quality" value
intent | IPP "print-rendering-intent" value
orientation | IPP "orientation-requested" value
sides | IPP "sides" value
type | PWG raster type string
xdpi | Cross-feed direction (horizontal) resolution
ydpi | Feed direction (vertical) resolution
sheet_back | Transform for back side or `NULL` for none

#### Return Value

`true` on success, `false` on failure

#### Discussion

The "media" argument specifies the media to use. The "optimize", "quality", "intent", "orientation", and "sides" arguments specify additional IPP Job Template attribute values that are reflected in the raster header.
The "type" argument specifies a "pwg-raster-document-type-supported" value that controls the color space and bit depth of the raster data. Supported values include:

- "adobe-rgb_8": 8-bit per component (24-bit) AdobeRGB
- "adobe-rgb_16": 16-bit per component (48-bit) AdobeRGB
- "black_1": 1-bit black (K)
- "black_8": 8-bit black (K)
- "black_16": 16-bit black (K)
- "cmyk_8": 8-bit per component (32-bit) CMYK
- "cmyk_16": 16-bit per component (64-bit) CMYK
- "device1_8" to "device15_8": 8-bit per component DeviceN
- "device1_16" to "device15_16": 16-bit per component DeviceN
- "rgb_8": 8-bit per component (24-bit) DeviceRGB
- "rgb_16": 16-bit per component (32-bit) DeviceRGB
- "sgray_1": 1-bit sGray
- "sgray_8": 8-bit sGray
- "sgray_16": 16-bit sGray
- "srgb_8": 8-bit per component (24-bit) sRGB
- "srgb_16": 16-bit per component (48-bit) sRGB

The "xres" and "yres" arguments specify the raster resolution in dots per inch.
The "sheet_back" argument specifies a "pwg-raster-document-sheet-back" value to apply for the back side of a page. Pass `NULL` for the front side.

### cupsRasterOpen

Open a raster stream using a file descriptor.

cups_raster_t *cupsRasterOpen(int fd, cups_raster_mode_t mode);

#### Parameters

fd | File descriptor
mode | Mode - `CUPS_RASTER_READ`, `CUPS_RASTER_WRITE`, `CUPS_RASTER_WRITE_COMPRESSED`, `CUPS_RASTER_WRITE_PWG`

#### Return Value

New stream

#### Discussion

This function associates a raster stream with the given file descriptor. For most printer driver filters, "fd" will be 0 (stdin). For most raster image processor (RIP) filters that generate raster data, "fd" will be 1 (stdout).
When writing raster data, the `CUPS_RASTER_WRITE`, `CUPS_RASTER_WRITE_COMPRESS`, or `CUPS_RASTER_WRITE_PWG` mode can be used - compressed and PWG output is generally 25-50% smaller but adds a 100-300% execution time overhead.

### cupsRasterOpenIO

Open a raster stream using a callback function.

cups_raster_t *cupsRasterOpenIO(cups_raster_cb_t iocb, void *ctx, cups_raster_mode_t mode);

#### Parameters

iocb | Read/write callback
ctx | Context pointer for callback
mode | Mode - `CUPS_RASTER_READ`, `CUPS_RASTER_WRITE`, `CUPS_RASTER_WRITE_COMPRESSED`, `CUPS_RASTER_WRITE_PWG`

#### Return Value

New stream

#### Discussion

This function associates a raster stream with the given callback function and context pointer.
When writing raster data, the `CUPS_RASTER_WRITE`, `CUPS_RASTER_WRITE_COMPRESS`, or `CUPS_RASTER_WRITE_PWG` mode can be used - compressed and PWG output is generally 25-50% smaller but adds a 100-300% execution time overhead.

### cupsRasterReadHeader

Read a raster page header.

bool cupsRasterReadHeader(cups_raster_t *r, cups_page_header_t *h);

#### Parameters

r | Raster stream
h | Pointer to header data

#### Return Value

`true` on success, `false` on failure

### cupsRasterReadPixels

Read raster pixels.

unsigned cupsRasterReadPixels(cups_raster_t *r, unsigned char *p, unsigned len);

#### Parameters

r | Raster stream
p | Pointer to pixel buffer
len | Number of bytes to read

#### Return Value

Number of bytes read

#### Discussion

For best performance, filters should read one or more whole lines. The "cupsBytesPerLine" value from the page header can be used to allocate the line buffer and as the number of bytes to read.

### cupsRasterWriteHeader

Write a raster page header.

bool cupsRasterWriteHeader(cups_raster_t *r, cups_page_header_t *h);

#### Parameters

r | Raster stream
h | Pointer to header data

#### Return Value

`true` on success, `false` on failure

### cupsRasterWritePixels

Write raster pixels.

unsigned cupsRasterWritePixels(cups_raster_t *r, unsigned char *p, unsigned len);

#### Parameters

r | Raster stream
p | Bytes to write
len | Number of bytes to write

#### Return Value

Number of bytes written

#### Discussion

For best performance, filters should write one or more whole lines. The "cupsBytesPerLine" value from the page header can be used to allocate the line buffer and as the number of bytes to write.

### cupsReadResponseData

Read additional data after the IPP response.

ssize_t cupsReadResponseData(http_t *http, char *buffer, size_t length);

#### Parameters

http | Connection to server or `CUPS_HTTP_DEFAULT`
buffer | Buffer to use
length | Number of bytes to read

#### Return Value

Bytes read, 0 on EOF, -1 on error

#### Discussion

This function is used after `cupsGetResponse` to read any trailing document data after an IPP response.

### cupsRemoveDest

Remove a destination from the destination list.

size_t cupsRemoveDest(const char *name, const char *instance, size_t num_dests, cups_dest_t **dests);

#### Parameters

name | Destination name
instance | Instance name or `NULL`
num_dests | Number of destinations
dests | Destinations

#### Return Value

New number of destinations

#### Discussion

Removing a destination/instance does not delete the class or printer queue, merely the lpoptions for that destination/instance. Use the `cupsSetDests` function to save the new options for the user.

### cupsRemoveOption

Remove an option from an option array.

size_t cupsRemoveOption(const char *name, size_t num_options, cups_option_t **options);

#### Parameters

name | Option name
num_options | Current number of options
options | Options

#### Return Value

New number of options

### cupsSaveCredentials

Save the credentials associated with a printer/server.

bool cupsSaveCredentials(const char *path, const char *common_name, const char *credentials, const char *key);

#### Parameters

path | Directory path for certificate/key store or `NULL` for default
common_name | Common name for certificate
credentials | PEM-encoded certificate chain or `NULL` to remove
key | PEM-encoded private key or `NULL` for none

#### Return Value

`true` on success, `false` on failure

#### Discussion

This function saves the the PEM-encoded X.509 certificate chain string and private key (if not `NULL`) to the directory "path" or, if "path" is `NULL`, in a per-user or system-wide (when running as root) certificate/key store.

### cupsSendRequest

Send an IPP request.

http_status_t cupsSendRequest(http_t *http, ipp_t *request, const char *resource, size_t length);

#### Parameters

http | Connection to server or `CUPS_HTTP_DEFAULT`
request | IPP request
resource | Resource path
length | Length of data to follow or `CUPS_LENGTH_VARIABLE`

#### Return Value

Initial HTTP status

#### Discussion

Use `cupsWriteRequestData` to write any additional data (document, etc.) for the request, `cupsGetResponse` to get the IPP response, and `cupsReadResponseData` to read any additional data following the response. Only one request can be sent/queued at a time per `http_t` connection.
Returns the initial HTTP status code, which will be `HTTP_STATUS_CONTINUE` on a successful send of the request.
Note: Unlike `cupsDoFileRequest`, `cupsDoIORequest`, and `cupsDoRequest`, the request is NOT freed with `ippDelete`.

### cupsSetClientCredentials

Set the default credentials to be used for TLS connections.

bool cupsSetClientCredentials(const char *credentials, const char *key);

#### Parameters

credentials | PEM-encoded X.509 credentials string
key | PEM-encoded private key

#### Return Value

`true` on success, `false` on failure

#### Discussion

Note: The default credentials are tracked separately for each thread in a program. Multi-threaded programs that override the setting need to do so in each thread for the same setting to be used.

### cupsSetDefaultDest

Set the default destination.

void cupsSetDefaultDest(const char *name, const char *instance, size_t num_dests, cups_dest_t *dests);

#### Parameters

name | Destination name
instance | Instance name or `NULL`
num_dests | Number of destinations
dests | Destinations

### cupsSetDests

Save the list of destinations for the specified server.

bool cupsSetDests(http_t *http, size_t num_dests, cups_dest_t *dests);

#### Parameters

http | Connection to server or `CUPS_HTTP_DEFAULT`
num_dests | Number of destinations
dests | Destinations

#### Return Value

`true` on success, `false` on error

#### Discussion

This function saves the destinations to /etc/cups/lpoptions when run as root and ~/.../lpoptions when run as a normal user.

### cupsSetEncryption

Set the encryption preference.

void cupsSetEncryption(http_encryption_t e);

#### Parameters

e | New encryption preference

#### Discussion

The default encryption setting comes from the CUPS_ENCRYPTION environment variable, then the ~/.cups/client.conf file, and finally the /etc/cups/client.conf file. If not set, the default is `HTTP_ENCRYPTION_IF_REQUESTED`.
Note: The current encryption setting is tracked separately for each thread in a program. Multi-threaded programs that override the setting need to do so in each thread for the same setting to be used.

### cupsSetOAuthCB

Set the OAuth 2.0 callback for CUPS.

void cupsSetOAuthCB(cups_oauth_cb_t cb, void *cb_data);

#### Parameters

cb | Callback function
cb_data | Callback data pointer

#### Discussion

This function sets the OAuth 2.0 callback for the various CUPS APIs that send HTTP requests. Pass `NULL` to disable OAuth authorization.
The OAuth callback receives the HTTP connection, realm name, scope name (if any), resource path, and the "user_data" pointer for each request that requires an OAuth access token. The function then returns either the Bearer token string or `NULL` if no authorization could be obtained.
Beyond reusing the Bearer token for subsequent requests on the same HTTP connection, no caching of the token is done by the CUPS library. The callback can determine whether to refresh a cached token by examining any existing token returned by the `httpGetAuthString` function.
Note: The current OAuth callback is tracked separately for each thread in a program. Multi-threaded programs that override the callback need to do so in each thread for the same callback to be used.

### cupsSetPasswordCB

Set the password callback for CUPS.

void cupsSetPasswordCB(cups_password_cb_t cb, void *cb_data);

#### Parameters

cb | Callback function
cb_data | Callback data pointer

#### Discussion

Pass `NULL` to restore the default (console) password callback, which reads the password from the console.
Note: The current password callback is tracked separately for each thread in a program. Multi-threaded programs that override the callback need to do so in each thread for the same callback to be used.

### cupsSetServer

Set the default server name and port.

void cupsSetServer(const char *server);

#### Parameters

server | Server name

#### Discussion

The "server" string can be a fully-qualified hostname, a numeric IPv4 or IPv6 address, or a domain socket pathname. Hostnames and numeric IP addresses can be optionally followed by a colon and port number to override the default port 631, e.g. "hostname:8631". Pass `NULL` to restore the default server name and port.
Note: The current server is tracked separately for each thread in a program. Multi-threaded programs that override the server need to do so in each thread for the same server to be used.

### cupsSetServerCredentials

Set the default server credentials.

bool cupsSetServerCredentials(const char *path, const char *common_name, bool auto_create);

#### Parameters

path | Directory path for certificate/key store or `NULL` for default
common_name | Default common name for server
auto_create | `true` = automatically create self-signed certificates

#### Return Value

`true` on success, `false` on failure

#### Discussion

Note: The server credentials are used by all threads in the running process. This function is threadsafe.

### cupsSetUser

Set the default user name.

void cupsSetUser(const char *user);

#### Parameters

user | User name

#### Discussion

Pass `NULL` to restore the default user name.
Note: The current user name is tracked separately for each thread in a program. Multi-threaded programs that override the user name need to do so in each thread for the same user name to be used.

### cupsSetUserAgent

Set the default HTTP User-Agent string.

void cupsSetUserAgent(const char *user_agent);

#### Parameters

user_agent | User-Agent string or `NULL`

#### Discussion

Setting the string to NULL forces the default value containing the CUPS version, IPP version, and operating system version and architecture.

### cupsSignCredentialsRequest

Sign an X.509 certificate signing request to produce an X.509 certificate chain.

bool cupsSignCredentialsRequest(const char *path, const char *common_name, const char *request, const char *root_name, cups_credpurpose_t allowed_purpose, cups_credusage_t allowed_usage, cups_cert_san_cb_t cb, void *cb_data, time_t expiration_date);

#### Parameters

path | Directory path for certificate/key store or `NULL` for default
common_name | Common name to use
request | PEM-encoded CSR
root_name | Root certificate
allowed_purpose | Allowed credential purpose(s)
allowed_usage | Allowed credential usage(s)
cb | subjectAltName callback or `NULL` to allow just .local
cb_data | Callback data
expiration_date | Certificate expiration date

#### Return Value

`true` on success, `false` on failure

#### Discussion

This function creates an X.509 certificate from a signing request. The certificate is stored in the directory "path" or, if "path" is `NULL`, in a per-user or system-wide (when running as root) certificate/key store. The generated certificate is signed by the named root certificate or, if "root_name" is `NULL`, a site-wide default root certificate. When "root_name" is `NULL` and there is no site-wide default root certificate, a self-signed certificate is generated instead.
The "allowed_purpose" argument specifies the allowed purpose(s) used for the credentials as a bitwise OR of the following constants:

- `CUPS_CREDPURPOSE_SERVER_AUTH` for validating TLS servers,
- `CUPS_CREDPURPOSE_CLIENT_AUTH` for validating TLS clients,
- `CUPS_CREDPURPOSE_CODE_SIGNING` for validating compiled code,
- `CUPS_CREDPURPOSE_EMAIL_PROTECTION` for validating email messages,
- `CUPS_CREDPURPOSE_TIME_STAMPING` for signing timestamps to objects, and/or
- `CUPS_CREDPURPOSE_OCSP_SIGNING` for Online Certificate Status Protocol message signing.

The "allowed_usage" argument specifies the allowed usage(s) for the credentials as a bitwise OR of the following constants:

- `CUPS_CREDUSAGE_DIGITAL_SIGNATURE`: digital signatures,
- `CUPS_CREDUSAGE_NON_REPUDIATION`: non-repudiation/content commitment,
- `CUPS_CREDUSAGE_KEY_ENCIPHERMENT`: key encipherment,
- `CUPS_CREDUSAGE_DATA_ENCIPHERMENT`: data encipherment,
- `CUPS_CREDUSAGE_KEY_AGREEMENT`: key agreement,
- `CUPS_CREDUSAGE_KEY_CERT_SIGN`: key certicate signing,
- `CUPS_CREDUSAGE_CRL_SIGN`: certificate revocation list signing,
- `CUPS_CREDUSAGE_ENCIPHER_ONLY`: encipherment only,
- `CUPS_CREDUSAGE_DECIPHER_ONLY`: decipherment only,
- `CUPS_CREDUSAGE_DEFAULT_CA`: defaults for CA certificates,
- `CUPS_CREDUSAGE_DEFAULT_TLS`: defaults for TLS certificates, and/or
- `CUPS_CREDUSAGE_ALL`: all usages.

The "cb" and "cb_data" arguments specify a function and its data that are used to validate any subjectAltName values in the signing request:

    bool san_cb(const char *common_name, const char *alt_name, void *cb_data) {
      ... return true if OK and false if not ...
    }

If `NULL`, a default validation function is used that allows "localhost" and variations of the common name.
The "expiration_date" argument specifies the expiration date and time as a Unix `time_t` value in seconds.

### cupsStartDestDocument

Start a new document.

http_status_t cupsStartDestDocument(http_t *http, cups_dest_t *dest, cups_dinfo_t *info, int job_id, const char *docname, const char *format, size_t num_options, cups_option_t *options, bool last_document);

#### Parameters

http | Connection to destination
dest | Destination
info | Destination information
job_id | Job ID
docname | Document name
format | Document format
num_options | Number of document options
options | Document options
last_document | `true` if this is the last document

#### Return Value

Status of document creation

#### Discussion

This function starts a new document for the specified destination "dest" and job "job_id". The "info" argument contains information about the destination obtained using the `cupsCopyDestInfo` function.
The "docname" argument specifies the name of the document/file being printed. The "format" argument specifies the MIME media type for the document; the following constants are provided for convenience:

- `CUPS_FORMAT_AUTO`: Auto-type the file using its contents
- `CUPS_FORMAT_JPEG`: JPEG image file
- `CUPS_FORMAT_PDF`: PDF file
- `CUPS_FORMAT_TEXT`: Plain text file

The "num_options" and "options" arguments provide the options to be applied to the document. The "last_document" argument specifies whether this is the final document in the job (`true`) or not (`false`).
Returns `HTTP_CONTINUE` on success.

### cupsThreadCancel

Cancel (kill) a thread.

void cupsThreadCancel(cups_thread_t thread);

#### Parameters

thread | Thread ID

### cupsThreadCreate

Create a thread.

cups_thread_t cupsThreadCreate(cups_thread_func_t func, void *arg);

#### Parameters

func | Entry point
arg | Entry point context

#### Return Value

Thread ID or `CUPS_THREAD_INVALID` on failure

### cupsThreadDetach

Tell the OS that the thread is running independently.

void cupsThreadDetach(cups_thread_t thread);

#### Parameters

thread | Thread ID

### cupsThreadWait

Wait for a thread to exit.

void *cupsThreadWait(cups_thread_t thread);

#### Parameters

thread | Thread ID

#### Return Value

Return value

### cupsUTF32ToUTF8

Convert UTF-32 to UTF-8.

ssize_t cupsUTF32ToUTF8(char *dest, const cups_utf32_t *src, const size_t maxout);

#### Parameters

dest | Target string
src | Source string
maxout | Max output in bytes

#### Return Value

Number of bytes or `-1` on error

#### Discussion

This function converts a UTF-32 (32-bit encoding of Unicode) string to a UTF-8 (8-bit encoding of Unicode) `nul`-terminated C string.

### cupsUTF8ToCharset

Convert UTF-8 to legacy character set.

ssize_t cupsUTF8ToCharset(char *dest, const char *src, const size_t maxout, const cups_encoding_t encoding);

#### Parameters

dest | Target string
src | Source string
maxout | Max output in bytes
encoding | Encoding

#### Return Value

Number of bytes or `-1` on error

### cupsUTF8ToUTF32

Convert UTF-8 to UTF-32.

ssize_t cupsUTF8ToUTF32(cups_utf32_t *dest, const char *src, const size_t maxout);

#### Parameters

dest | Target string
src | Source string
maxout | Max output in words

#### Return Value

Number of words or `-1` on error

#### Discussion

This function converts a UTF-8 (8-bit encoding of Unicode) `nul`-terminated C string to a UTF-32 (32-bit encoding of Unicode) string.

### cupsWriteRequestData

Write additional data after an IPP request.

http_status_t cupsWriteRequestData(http_t *http, const char *buffer, size_t length);

#### Parameters

http | Connection to server or `CUPS_HTTP_DEFAULT`
buffer | Bytes to write
length | Number of bytes to write

#### Return Value

`HTTP_STATUS_CONTINUE` if OK or HTTP status on error

#### Discussion

This function writes a buffer of additional data after an IPP request and is used after calling the `cupsSendRequest` and/or `cupsStartDocument` functions, typically to send all or part of a document or file. Each call appends the given buffer of data to the request, allowing an application to stream content to the receiving IPP server.
Call the `cupsGetResponse` or `cupsFinishDestDocument` functions to complete the current request and get the corresponding response.

### httpAcceptConnection

Accept a new HTTP client connection.

http_t *httpAcceptConnection(int fd, bool blocking);

#### Parameters

fd | Listen socket file descriptor
blocking | `true` if the connection should be blocking, `false` otherwise

#### Return Value

HTTP connection or `NULL`

#### Discussion

This function accepts a new HTTP client connection from the specified listening socket "fd". The "blocking" argument specifies whether the new HTTP connection is blocking.

### httpAddrClose

Close a socket created by `httpAddrConnect` or `httpAddrListen`.

bool httpAddrClose(http_addr_t *addr, int fd);

#### Parameters

addr | Listen address or `NULL`
fd | Socket file descriptor

#### Return Value

`true` on success, `false` on failure

#### Discussion

Pass `NULL` for sockets created with `httpAddrConnect` and the listen address for sockets created with `httpAddrListen`. This function ensures that domain sockets are removed when closed.

### httpAddrConnect

Connect to any of the addresses in the list with a timeout and optional cancel.

http_addrlist_t *httpAddrConnect(http_addrlist_t *addrlist, int *sock, int msec, int *cancel);

#### Parameters

addrlist | List of potential addresses
sock | Socket
msec | Timeout in milliseconds
cancel | Pointer to "cancel" variable

#### Return Value

Connected address or NULL on failure

### httpAddrCopyList

Copy an address list.

http_addrlist_t *httpAddrCopyList(void);

#### Return Value

New address list or `NULL` on error

### httpAddrFreeList

Free an address list.

void httpAddrFreeList(void);

### httpAddrGetFamily

Get the address family of an address.

int httpAddrGetFamily(http_addr_t *addr);

#### Parameters

addr | Address

#### Return Value

Address family

### httpAddrGetLength

Return the length of the address in bytes.

size_t httpAddrGetLength(const http_addr_t *addr);

#### Parameters

addr | Address

#### Return Value

Length in bytes

### httpAddrGetList

Get a list of addresses for a hostname.

http_addrlist_t *httpAddrGetList(void);

#### Return Value

List of addresses or NULL

### httpAddrGetPort

Get the port number associated with an address.

int httpAddrGetPort(http_addr_t *addr);

#### Parameters

addr | Address

#### Return Value

Port number

### httpAddrGetString

Convert an address to a numeric string.

char *httpAddrGetString(const http_addr_t *addr, char *s, size_t slen);

#### Parameters

addr | Address to convert
s | String buffer
slen | Length of string buffer

#### Return Value

Numeric address string

### httpAddrIsAny

Check for the "any" address.

bool httpAddrIsAny(const http_addr_t *addr);

#### Parameters

addr | Address to check

#### Return Value

`true` if "any", `false` otherwise

### httpAddrIsEqual

Compare two addresses.

bool httpAddrIsEqual(const http_addr_t *addr1, const http_addr_t *addr2);

#### Parameters

addr1 | First address
addr2 | Second address

#### Return Value

`true` if equal, `false` if not

### httpAddrIsLocalhost

Check for the local loopback address.

bool httpAddrIsLocalhost(const http_addr_t *addr);

#### Parameters

addr | Address to check

#### Return Value

`true` if local host, `false` otherwise

### httpAddrListen

Create a listening socket bound to the specified address and port.

int httpAddrListen(http_addr_t *addr, int port);

#### Parameters

addr | Address to bind to
port | Port number to bind to

#### Return Value

Socket or `-1` on error

### httpAddrLookup

Lookup the hostname associated with the address.

char *httpAddrLookup(const http_addr_t *addr, char *name, size_t namelen);

#### Parameters

addr | Address to lookup
name | Host name buffer
namelen | Size of name buffer

#### Return Value

Host name

### httpAddrSetPort

Set the port number associated with an address.

void httpAddrSetPort(http_addr_t *addr, int port);

#### Parameters

addr | Address
port | Port

### httpAssembleURI

Assemble a uniform resource identifier from its components.

http_uri_status_t httpAssembleURI(http_uri_coding_t encoding, char *uri, size_t urilen, const char *scheme, const char *username, const char *host, int port, const char *resource);

#### Parameters

encoding | Encoding flags
uri | URI buffer
urilen | Size of URI buffer
scheme | Scheme name
username | Username
host | Hostname or address
port | Port number
resource | Resource

#### Return Value

URI status

#### Discussion

This function escapes reserved characters in the URI depending on the value of the "encoding" argument. You should use this function in place of traditional string functions whenever you need to create a URI string.

### httpAssembleURIf

Assemble a uniform resource identifier from its components with a formatted resource.

http_uri_status_t httpAssembleURIf(http_uri_coding_t encoding, char *uri, size_t urilen, const char *scheme, const char *username, const char *host, int port, const char *resourcef, ...);

#### Parameters

encoding | Encoding flags
uri | URI buffer
urilen | Size of URI buffer
scheme | Scheme name
username | Username
host | Hostname or address
port | Port number
resourcef | Printf-style resource
... | Additional arguments as needed

#### Return Value

URI status

#### Discussion

This function creates a formatted version of the resource string argument "resourcef" and escapes reserved characters in the URI depending on the value of the "encoding" argument. You should use this function in place of traditional string functions whenever you need to create a URI string.

### httpAssembleUUID

Assemble a name-based UUID URN conforming to RFC 4122.

char *httpAssembleUUID(const char *server, int port, const char *name, int number, char *buffer, size_t bufsize);

#### Parameters

server | Server name
port | Port number
name | Object name or NULL
number | Object number or 0
buffer | String buffer
bufsize | Size of buffer

#### Return Value

UUID string

#### Discussion

This function creates a unique 128-bit identifying number using the server name, port number, random data, and optionally an object name and/or object number. The result is formatted as a UUID URN as defined in RFC 4122.
The buffer needs to be at least 46 bytes in size.

### httpClearCookie

Clear the cookie value(s).

void httpClearCookie(http_t *http);

#### Parameters

http | HTTP connection

### httpClearFields

Clear HTTP request/response fields.

void httpClearFields(http_t *http);

#### Parameters

http | HTTP connection

### httpClose

Close a HTTP connection.

void httpClose(http_t *http);

#### Parameters

http | HTTP connection

### httpConnect

Connect to a HTTP server.

http_t *httpConnect(const char *host, int port, http_addrlist_t *addrlist, int family, http_encryption_t encryption, bool blocking, int msec, int *cancel);

#### Parameters

host | Host to connect to
port | Port number
addrlist | List of addresses or `NULL` to lookup
family | Address family to use or `AF_UNSPEC` for any
encryption | Type of encryption to use
blocking | `true` for blocking connection, `false` for non-blocking
msec | Connection timeout in milliseconds, `0` means don't connect
cancel | Pointer to "cancel" variable or `NULL` for none

#### Return Value

New HTTP connection

#### Discussion

This function creates a connection to a HTTP server. The "host" and "port" arguments specify a hostname or IP address and port number to use while the "addrlist" argument specifies a list of addresses to use or `NULL` to do a fresh lookup. The "family" argument specifies the address family to use - `AF_UNSPEC` to try both IPv4 and IPv6, `AF_INET` for IPv4, or `AF_INET6` for IPv6.
The "encryption" argument specifies whether to encrypt the connection and the "blocking" argument specifies whether to use blocking behavior when reading or writing data.
The "msec" argument specifies how long to try to connect to the server or `0` to just create an unconnected `http_t` object. The "cancel" argument specifies an integer variable that can be set to a non-zero value to cancel the connection process.

### httpConnectAgain

Reconnect to a HTTP server with timeout and optional cancel variable.

bool httpConnectAgain(http_t *http, int msec, int *cancel);

#### Parameters

http | HTTP connection
msec | Timeout in milliseconds
cancel | Pointer to "cancel" variable

#### Return Value

`true` on success, `false` on failure

### httpConnectURI

Connect to a HTTP service using a URI.

http_t *httpConnectURI(const char *uri, char *host, size_t hsize, int *port, char *resource, size_t rsize, bool blocking, int msec, int *cancel, bool require_ca);

#### Parameters

uri | Service to connect to
host | Host name buffer (`NULL` for don't care)
hsize | Size of host name buffer
port | Port number (`NULL` for don't care)
resource | Resource path buffer (`NULL` for don't care)
rsize | Size of resource path buffer
blocking | `true` for blocking connection, `false` for non-blocking
msec | Connection timeout in milliseconds, `0` means don't connect
cancel | Pointer to "cancel" variable or `NULL` for none
require_ca | `true` to require a CA-signed X.509 certificate

#### Return Value

New HTTP connection

#### Discussion

This function creates a connection to a HTTP server. The "uri" argument specifies a "http", "https", "ipp", or "ipps" URI for the service.
The resource path for the service is returned in the buffer pointed to by the "resource" argument of size "rsize".
The "msec" argument specifies how long to try to connect to the server or `0` to just create an unconnected `http_t` object. The "cancel" argument specifies an integer variable that can be set to a non-zero value to cancel the connection process.
The "require_ca" argument specifies whether to verify that the service connection is using a CA-signed X.509 certificate.

### httpCopyPeerCredentials

Copy the credentials associated with the peer in an encrypted connection.

char *httpCopyPeerCredentials(http_t *http);

#### Parameters

http | Connection to server

#### Return Value

PEM-encoded X.509 certificate chain or `NULL`

### httpDecode64

Base64-decode a string.

char *httpDecode64(char *out, size_t *outlen, const char *in, const char **end);

#### Parameters

out | String to write to
outlen | Size of output string
in | String to read from
end | Pointer to end of Base64 data (`NULL` if don't care)

#### Return Value

Decoded string or `NULL` on error

#### Discussion

This function decodes a Base64 string as defined by RFC 4648. The caller must initialize "outlen" to the maximum size of the decoded string. On return "outlen" contains the decoded length of the string and "end" (if not `NULL`) points to the end of the Base64 data that has been decoded.
This function always reserves one byte in the output buffer for a nul terminating character, even if the result is not a regular string. Callers should ensure that the output buffer is at least one byte larger than the expected size, for example 33 bytes for a SHA-256 hash which is 32 bytes in length.
This function supports both Base64 and Base64url strings.

### httpEncode64

Base64-encode a string.

char *httpEncode64(char *out, size_t outlen, const char *in, size_t inlen, bool url);

#### Parameters

out | String to write to
outlen | Maximum size of output string
in | String to read from
inlen | Size of input string
url | `true` for Base64url, `false` for Base64

#### Return Value

Encoded string

#### Discussion

This function encodes a Base64 string as defined by RFC 4648. The "url" argument controls whether the original Base64 ("url" = `false`) or the Base64url ("url" = `true`) alphabet is used.

### httpFieldValue

Return the HTTP field enumeration value for a field name.

http_field_t httpFieldValue(const char *name);

#### Parameters

name | String name

#### Return Value

Field index

### httpFlush

Flush data read from a HTTP connection.

void httpFlush(http_t *http);

#### Parameters

http | HTTP connection

### httpFlushWrite

Flush data written to a HTTP connection.

int httpFlushWrite(http_t *http);

#### Parameters

http | HTTP connection

#### Return Value

Bytes written or -1 on error

### httpGetActivity

Get the most recent activity for a connection.

time_t httpGetActivity(http_t *http);

#### Parameters

http | HTTP connection

#### Return Value

Time of last read or write

#### Discussion

The return value is the time in seconds of the last read or write.

### httpGetAddress

Get the address of the connected peer of a connection.

http_addr_t *httpGetAddress(http_t *http);

#### Parameters

http | HTTP connection

#### Return Value

Connected address or `NULL`

#### Discussion

For connections created with `httpConnect2`, the address is for the server. For connections created with `httpAccept`, the address is for the client.
Returns `NULL` if the socket is currently unconnected.

### httpGetAuthString

Get the current authorization string.

const char *httpGetAuthString(http_t *http);

#### Parameters

http | HTTP connection

#### Return Value

Authorization string

#### Discussion

The authorization string is set by `cupsDoAuthentication` and `httpSetAuthString`. Use `httpGetAuthString` to retrieve the string to use with `httpSetField` for the `HTTP_FIELD_AUTHORIZATION` value.

### httpGetBlocking

Get the blocking/non-blocking state of a connection.

bool httpGetBlocking(http_t *http);

#### Parameters

http | HTTP connection

#### Return Value

`true` if blocking, `false` if non-blocking

### httpGetContentEncoding

Get a common content encoding, if any, between the client and server.

const char *httpGetContentEncoding(http_t *http);

#### Parameters

http | HTTP connection

#### Return Value

Content-Coding value or `NULL` for the identity coding.

#### Discussion

This function uses the value of the Accepts-Encoding HTTP header and must be called after receiving a response from the server or a request from the client. The value returned can be use in subsequent requests (for clients) or in the response (for servers) in order to compress the content stream.

### httpGetCookie

Get cookie data from the HTTP connection.

const char *httpGetCookie(http_t *http);

#### Parameters

http | HTTP connection

#### Return Value

Cookie data or `NULL`

#### Discussion

This function returns any HTTP "Set-Cookie:" or "Cookie:" header data for the given HTTP connection as described in RFC 6265. Use the `httpGetCookieValue` to get the value of a named "Cookie:" value.

### httpGetCookieValue

Get the value of a named cookie from the HTTP connection.

char *httpGetCookieValue(http_t *http, const char *name, char *buffer, size_t bufsize);

#### Parameters

http | HTTP connection
name | Cookie name
buffer | Value buffer
bufsize | Size of value buffer

#### Return Value

Cookie value or `NULL` if not present

#### Discussion

This function copies the value of a named cookie in the HTTP "Cookie:" header for the given HTTP connection as described in RFC 6265. Use the `httpGetCookie` function to get the original "Cookie:" string.

### httpGetDateString

Get a formatted date/time string from a time value.

const char *httpGetDateString(time_t t, char *s, size_t slen);

#### Parameters

t | Time in seconds
s | String buffer
slen | Size of string buffer

#### Return Value

Date/time string

### httpGetDateTime

Get a time value from a formatted date/time string.

time_t httpGetDateTime(const char *s);

#### Parameters

s | Date/time string

#### Return Value

Time in seconds

### httpGetEncryption

Get the current encryption mode of a connection.

http_encryption_t httpGetEncryption(http_t *http);

#### Parameters

http | HTTP connection

#### Return Value

Current encryption mode

#### Discussion

This function returns the encryption mode for the connection. Use the `httpIsEncrypted` function to determine whether a TLS session has been established.

### httpGetError

Get the last error on a connection.

int httpGetError(http_t *http);

#### Parameters

http | HTTP connection

#### Return Value

Error code (errno) value

### httpGetExpect

Get the value of the Expect header, if any.

http_status_t httpGetExpect(http_t *http);

#### Parameters

http | HTTP connection

#### Return Value

Expect: status, if any

#### Discussion

Returns `HTTP_STATUS_NONE` if there is no Expect header, otherwise returns the expected HTTP status code, typically `HTTP_STATUS_CONTINUE`.

### httpGetFd

Get the file descriptor associated with a connection.

int httpGetFd(http_t *http);

#### Parameters

http | HTTP connection

#### Return Value

File descriptor or -1 if none

### httpGetField

Get a field value from a request/response.

const char *httpGetField(http_t *http, http_field_t field);

#### Parameters

http | HTTP connection
field | Field to get

#### Return Value

Field value

### httpGetHostname

Get the FQDN for the connection or local system.

const char *httpGetHostname(http_t *http, char *s, size_t slen);

#### Parameters

http | HTTP connection or NULL
s | String buffer for name
slen | Size of buffer

#### Return Value

FQDN for connection or system

#### Discussion

When "http" points to a connected socket, return the hostname or address that was used in the call to `httpConnect` or the address of the client for the connection from `httpAcceptConnection`.
When "http" is `NULL`, return the FQDN for the local system.

### httpGetKeepAlive

Get the current Keep-Alive state of the connection.

http_keepalive_t httpGetKeepAlive(http_t *http);

#### Parameters

http | HTTP connection

#### Return Value

Keep-Alive state

### httpGetLength

Get the amount of data remaining from the content-length or transfer-encoding fields.

off_t httpGetLength(http_t *http);

#### Parameters

http | HTTP connection

#### Return Value

Content length

#### Discussion

This function returns the complete content length, even for content larger than 2^31 - 1.

### httpGetPending

Get the number of bytes that are buffered for writing.

size_t httpGetPending(http_t *http);

#### Parameters

http | HTTP connection

#### Return Value

Number of bytes buffered

### httpGetReady

Get the number of bytes that can be read without blocking.

size_t httpGetReady(http_t *http);

#### Parameters

http | HTTP connection

#### Return Value

Number of bytes available

### httpGetRemaining

Get the number of remaining bytes in the message body or current chunk.

size_t httpGetRemaining(http_t *http);

#### Parameters

http | HTTP connection

#### Return Value

Remaining bytes

#### Discussion

The `httpIsChunked` function can be used to determine whether the message body is chunked or fixed-length.

### httpGetSecurity

Get the TLS version and cipher suite used by a connection.

const char *httpGetSecurity(http_t *http, char *buffer, size_t bufsize);

#### Parameters

http | HTTP connection
buffer | String buffer
bufsize | Size of buffer

#### Return Value

Security information or `NULL` if not encrypted

#### Discussion

This function gets the TLS version and cipher suite being used by a connection, if any. The string is copied to "buffer" and is of the form "TLS/major.minor CipherSuite". If not encrypted, the buffer is cleared to the empty string.

### httpGetState

Get the current state of the HTTP request.

http_state_t httpGetState(http_t *http);

#### Parameters

http | HTTP connection

#### Return Value

HTTP state

### httpGetStatus

Get the status of the last HTTP request.

http_status_t httpGetStatus(http_t *http);

#### Parameters

http | HTTP connection

#### Return Value

HTTP status

### httpGetSubField

Get a sub-field value.

char *httpGetSubField(http_t *http, http_field_t field, const char *name, char *value, size_t valuelen);

#### Parameters

http | HTTP connection
field | Field index
name | Name of sub-field
value | Value string
valuelen | Size of value buffer

#### Return Value

Value or `NULL`

### httpGetVersion

Get the HTTP version at the other end.

http_version_t httpGetVersion(http_t *http);

#### Parameters

http | HTTP connection

#### Return Value

Version number

### httpGets

Get a line of text from a HTTP connection.

char *httpGets(http_t *http, char *line, size_t length);

#### Parameters

http | HTTP connection
line | Line to read into
length | Max length of buffer

#### Return Value

Line or `NULL`

### httpInitialize

Initialize the HTTP interface library and set the default HTTP proxy (if any).

void httpInitialize(void);

### httpIsChunked

Report whether a message body is chunked.

bool httpIsChunked(http_t *http);

#### Parameters

http | HTTP connection

#### Return Value

`true` if chunked, `false` if not

#### Discussion

This function returns `true` if the message body is composed of variable-length chunks.

### httpIsEncrypted

Report whether a connection is encrypted.

bool httpIsEncrypted(http_t *http);

#### Parameters

http | HTTP connection

#### Return Value

`true` if encrypted, `false` if not

#### Discussion

This function returns `true` if the connection is currently encrypted.

### httpPeek

Peek at data from a HTTP connection.

ssize_t httpPeek(http_t *http, char *buffer, size_t length);

#### Parameters

http | HTTP connection
buffer | Buffer for data
length | Maximum number of bytes

#### Return Value

Number of bytes copied

#### Discussion

This function copies available data from the given HTTP connection, reading a buffer as needed. The data is still available for reading using `httpRead`.
For non-blocking connections the usual timeouts apply.

### httpPrintf

Print a formatted string to a HTTP connection.

ssize_t httpPrintf(http_t *http, const char *format, ...);

#### Parameters

http | HTTP connection
format | printf-style format string
... | Additional args as needed

#### Return Value

Number of bytes written or `-1` on error

### httpRead

Read data from a HTTP connection.

ssize_t httpRead(http_t *http, char *buffer, size_t length);

#### Parameters

http | HTTP connection
buffer | Buffer for data
length | Maximum number of bytes

#### Return Value

Number of bytes read

### httpReadRequest

Read a HTTP request from a connection.

http_state_t httpReadRequest(http_t *http, char *uri, size_t urilen);

#### Parameters

http | HTTP connection
uri | URI buffer
urilen | Size of URI buffer

#### Return Value

New state of connection

### httpResolveHostname

Resolve the hostname of the HTTP connection address.

const char *httpResolveHostname(http_t *http, char *buffer, size_t bufsize);

#### Parameters

http | HTTP connection
buffer | Hostname buffer or `NULL` to use HTTP buffer
bufsize | Size of buffer

#### Return Value

Resolved hostname or `NULL`

### httpResolveURI

Resolve a DNS-SD URI.

const char *httpResolveURI(const char *uri, char *resolved_uri, size_t resolved_size, http_resolve_t options, http_resolve_cb_t cb, void *cb_data);

#### Parameters

uri | DNS-SD URI
resolved_uri | Buffer for resolved URI
resolved_size | Size of URI buffer
options | Resolve options
cb | Continue callback function
cb_data | Context pointer for callback

#### Return Value

Resolved URI

#### Discussion

This function resolves a DNS-SD URI of the form "scheme://service-instance-name._protocol._tcp.domain/...". The "options" argument specifies a bitfield of resolution options including:

- `HTTP_RESOLVE_DEFAULT`: Use default options
- `HTTP_RESOLVE_FQDN`: Resolve the fully-qualified domain name instead of an IP address
- `HTTP_RESOLVE_FAXOUT`: Resolve the FaxOut service instead of Print (IPP/IPPS)

The "cb" argument specifies a callback that allows resolution to be terminated. The callback is provided the "cb_data" value and returns a `bool` value that is `true` to continue and `false` to stop. If no callback is specified ("cb" is `NULL`), then this function will block up to 90 seconds to resolve the specified URI.

### httpSeparateURI

Separate a Universal Resource Identifier into its components.

http_uri_status_t httpSeparateURI(http_uri_coding_t decoding, const char *uri, char *scheme, size_t schemelen, char *username, size_t usernamelen, char *host, size_t hostlen, int *port, char *resource, size_t resourcelen);

#### Parameters

decoding | Decoding flags
uri | Universal Resource Identifier
scheme | Scheme (http, https, etc.)
schemelen | Size of scheme buffer
username | Username
usernamelen | Size of username buffer
host | Hostname
hostlen | Size of hostname buffer
port | Port number to use
resource | Resource/filename
resourcelen | Size of resource buffer

#### Return Value

Result of separation

### httpSetAuthString

Set the current authorization string.

void httpSetAuthString(http_t *http, const char *scheme, const char *data);

#### Parameters

http | HTTP connection
scheme | Auth scheme (`NULL` to clear it)
data | Auth data (`NULL` for none)

#### Discussion

This function stores a copy of the current authorization string in the HTTP connection object. You must still call `httpSetField` to set `HTTP_FIELD_AUTHORIZATION` prior to issuing a HTTP request using `httpWriteRequest`.

### httpSetBlocking

Set blocking/non-blocking behavior on a connection.

void httpSetBlocking(http_t *http, bool blocking);

#### Parameters

http | HTTP connection
blocking | `true` = blocking, `false` = non-blocking

#### Discussion

This function sets whether a connection uses blocking behavior when reading or writing data. The "http" argument specifies the HTTP connection and the "blocking" argument specifies whether to use blocking behavior.

### httpSetCookie

Add Set-Cookie value(s).

void httpSetCookie(http_t *http, const char *cookie);

#### Parameters

http | Connection
cookie | Cookie string

#### Discussion

This function adds one or more Set-Cookie header values that will be sent to the client with the `httpWriteResponse` function. Each value conforms to the format defined in RFC 6265. Multiple values can be passed in the "cookie" string separated by a newline character.
Call the `httpClearCookies` function to clear all Set-Cookie values.

### httpSetDefaultField

Set the default value of a HTTP header.

void httpSetDefaultField(http_t *http, http_field_t field, const char *value);

#### Parameters

http | HTTP connection
field | Field index
value | Value

#### Discussion

This function sets the default value for a HTTP header.

> Note: Currently only the `HTTP_FIELD_ACCEPT_ENCODING`, `HTTP_FIELD_SERVER`, and `HTTP_FIELD_USER_AGENT` fields can be set.

### httpSetEncryption

Set the required encryption on a HTTP connection.

bool httpSetEncryption(http_t *http, http_encryption_t e);

#### Parameters

http | HTTP connection
e | New encryption preference

#### Return Value

`true` on success, `false` on error

### httpSetExpect

Set the Expect: header in a request.

void httpSetExpect(http_t *http, http_status_t expect);

#### Parameters

http | HTTP connection
expect | HTTP status to expect (`HTTP_STATUS_NONE` or `HTTP_STATUS_CONTINUE`)

#### Discussion

This function sets the `Expect:` header in a request. Currently only `HTTP_STATUS_NONE` or `HTTP_STATUS_CONTINUE` is supported for the "expect" argument.

### httpSetField

Set the value of a HTTP header.

void httpSetField(http_t *http, http_field_t field, const char *value);

#### Parameters

http | HTTP connection
field | Field index
value | Value

### httpSetKeepAlive

Set the current Keep-Alive state of a connection.

void httpSetKeepAlive(http_t *http, http_keepalive_t keep_alive);

#### Parameters

http | HTTP connection
keep_alive | New Keep-Alive value

### httpSetLength

Set the `Content-Length` and `Transfer-Encoding` fields.

void httpSetLength(http_t *http, size_t length);

#### Parameters

http | HTTP connection
length | Length (`0` for chunked)

#### Discussion

This function sets the `Content-Length` and `Transfer-Encoding` fields. Passing `0` to the "length" argument specifies a chunked transfer encoding while other values specify a fixed `Content-Length`.

### httpSetTimeout

Set read/write timeouts and an optional callback.

void httpSetTimeout(http_t *http, double timeout, http_timeout_cb_t cb, void *cb_data);

#### Parameters

http | HTTP connection
timeout | Number of seconds for timeout, must be greater than `0`
cb | Callback function or `NULL` for none
cb_data | Callback data pointer

#### Discussion

This function sets the read/write timeouts for a HTTP connection with an optional timeout callback. The timeout callback receives both the HTTP connection pointer and a user data pointer, and returns `true` to continue or `false` to error (time) out.

    bool // true to continue, false to stop
    timeout_cb(http_t *http, void *user_data)
    {
      ... "http" contains the HTTP connection, "user_data" contains the callback pointer
    }

### httpShutdown

Shutdown one side of a HTTP connection.

void httpShutdown(http_t *http);

#### Parameters

http | HTTP connection

### httpStateString

Return the string describing a HTTP state value.

const char *httpStateString(http_state_t state);

#### Parameters

state | HTTP state value

#### Return Value

State string

### httpStatusString

Return a short string describing a HTTP status code.

const char *httpStatusString(http_status_t status);

#### Parameters

status | HTTP status code

#### Return Value

Localized status string

#### Discussion

This function returns a short (localized) string describing a HTTP status code. The strings are taken from the IANA HTTP Status Code registry.

### httpURIStatusString

Return a string describing a URI status value.

const char *httpURIStatusString(http_uri_status_t status);

#### Parameters

status | URI status value

#### Return Value

Localized status string

#### Discussion

This function returns a short (localized) string describing a URI status value.

### httpUpdate

Update the current HTTP state for incoming data.

http_status_t httpUpdate(http_t *http);

#### Parameters

http | HTTP connection

#### Return Value

HTTP status

### httpWait

Wait for data available on a connection.

bool httpWait(http_t *http, int msec);

#### Parameters

http | HTTP connection
msec | Milliseconds to wait

#### Return Value

`true` when data is available, `false` otherwise

### httpWrite

Write data to a HTTP connection.

ssize_t httpWrite(http_t *http, const char *buffer, size_t length);

#### Parameters

http | HTTP connection
buffer | Buffer for data
length | Number of bytes to write

#### Return Value

Number of bytes written

#### Discussion

This function writes data to a HTTP connection. When using chunking or content coding, specifying a "length" of `0` will complete the current HTTP request/response message.

### httpWriteRequest

Write a HTTP request.

bool httpWriteRequest(http_t *http, const char *method, const char *uri);

#### Parameters

http | HTTP connection
method | Request method ("GET", "POST", "PUT", etc.)
uri | Request URI

#### Return Value

`true` on success, `false` on failure

#### Discussion

This function writes a HTTP request to the specified connection. The "method" argument specifies the HTTP method ("GET", "POST", "PUT", etc) while the "uri" argument specifies the request URI. All fields must be set using the `httpSetCookie`, `httpSetField`, and `httpSetLength` functions prior to writing the request.

### httpWriteResponse

Write a HTTP response to a client connection.

bool httpWriteResponse(http_t *http, http_status_t status);

#### Parameters

http | HTTP connection
status | Status code

#### Return Value

`true` on success, `false` on error

### ippAddBoolean

Add a boolean attribute to an IPP message.

ipp_attribute_t *ippAddBoolean(ipp_t *ipp, ipp_tag_t group, const char *name, bool value);

#### Parameters

ipp | IPP message
group | IPP group
name | Name of attribute
value | Value of attribute

#### Return Value

New attribute

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "group" argument specifies the IPP attribute group tag: none (`IPP_TAG_ZERO`, for member attributes), document (`IPP_TAG_DOCUMENT`), event notification (`IPP_TAG_EVENT_NOTIFICATION`), operation (`IPP_TAG_OPERATION`), printer (`IPP_TAG_PRINTER`), subscription (`IPP_TAG_SUBSCRIPTION`), or unsupported (`IPP_TAG_UNSUPPORTED_GROUP`).

### ippAddBooleans

Add an array of boolean values.

ipp_attribute_t *ippAddBooleans(ipp_t *ipp, ipp_tag_t group, const char *name, size_t num_values, const bool *values);

#### Parameters

ipp | IPP message
group | IPP group
name | Name of attribute
num_values | Number of values
values | Values

#### Return Value

New attribute

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "group" argument specifies the IPP attribute group tag: none (`IPP_TAG_ZERO`, for member attributes), document (`IPP_TAG_DOCUMENT`), event notification (`IPP_TAG_EVENT_NOTIFICATION`), operation (`IPP_TAG_OPERATION`), printer (`IPP_TAG_PRINTER`), subscription (`IPP_TAG_SUBSCRIPTION`), or unsupported (`IPP_TAG_UNSUPPORTED_GROUP`).

### ippAddCollection

Add a collection value.

ipp_attribute_t *ippAddCollection(ipp_t *ipp, ipp_tag_t group, const char *name, ipp_t *value);

#### Parameters

ipp | IPP message
group | IPP group
name | Name of attribute
value | Value

#### Return Value

New attribute

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "group" argument specifies the IPP attribute group tag: none (`IPP_TAG_ZERO`, for member attributes), document (`IPP_TAG_DOCUMENT`), event notification (`IPP_TAG_EVENT_NOTIFICATION`), operation (`IPP_TAG_OPERATION`), printer (`IPP_TAG_PRINTER`), subscription (`IPP_TAG_SUBSCRIPTION`), or unsupported (`IPP_TAG_UNSUPPORTED_GROUP`).
The "name" argument specifies the name of the attribute, while the "value" argument provides an IPP message containing the collection member attributes.

> Note: You must call the `ippDelete` function on the "value" argument to make sure the memory used by the value is released.

### ippAddCollections

Add an array of collection values.

ipp_attribute_t *ippAddCollections(ipp_t *ipp, ipp_tag_t group, const char *name, size_t num_values, const ipp_t **values);

#### Parameters

ipp | IPP message
group | IPP group
name | Name of attribute
num_values | Number of values
values | Values

#### Return Value

New attribute

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "group" argument specifies the IPP attribute group tag: none (`IPP_TAG_ZERO`, for member attributes), document (`IPP_TAG_DOCUMENT`), event notification (`IPP_TAG_EVENT_NOTIFICATION`), operation (`IPP_TAG_OPERATION`), printer (`IPP_TAG_PRINTER`), subscription (`IPP_TAG_SUBSCRIPTION`), or unsupported (`IPP_TAG_UNSUPPORTED_GROUP`).
The "name" argument specifies the name of the attribute, while the "num_values" and "values" arguments provide IPP messages containing the collection member attributes for each value.

> Note: You must call the `ippDelete` function on each of the "values" arguments to make sure the memory used by the value is released.

### ippAddCredentialsString

Add a credentials string attribute to an IPP message.

ipp_attribute_t *ippAddCredentialsString(ipp_t *ipp, ipp_tag_t group, const char *name, const char *credentials);

#### Parameters

ipp | IPP message
group | IPP group
name | Attribute name
credentials | Credentials string

#### Return Value

New attribute

#### Discussion

This function adds a 1setOf text attribute to an IPP message corresponding to the specified credentials string.
The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "group" argument specifies the IPP attribute group tag: none (`IPP_TAG_ZERO`, for member attributes), document (`IPP_TAG_DOCUMENT`), event notification (`IPP_TAG_EVENT_NOTIFICATION`), operation (`IPP_TAG_OPERATION`), printer (`IPP_TAG_PRINTER`), subscription (`IPP_TAG_SUBSCRIPTION`), or unsupported (`IPP_TAG_UNSUPPORTED_GROUP`).

### ippAddDate

Add a dateTime attribute to an IPP message.

ipp_attribute_t *ippAddDate(ipp_t *ipp, ipp_tag_t group, const char *name, const ipp_uchar_t *value);

#### Parameters

ipp | IPP message
group | IPP group
name | Name of attribute
value | Value

#### Return Value

New attribute

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "group" argument specifies the IPP attribute group tag: none (`IPP_TAG_ZERO`, for member attributes), document (`IPP_TAG_DOCUMENT`), event notification (`IPP_TAG_EVENT_NOTIFICATION`), operation (`IPP_TAG_OPERATION`), printer (`IPP_TAG_PRINTER`), subscription (`IPP_TAG_SUBSCRIPTION`), or unsupported (`IPP_TAG_UNSUPPORTED_GROUP`).

### ippAddInteger

Add a integer attribute to an IPP message.

ipp_attribute_t *ippAddInteger(ipp_t *ipp, ipp_tag_t group, ipp_tag_t value_tag, const char *name, int value);

#### Parameters

ipp | IPP message
group | IPP group
value_tag | Type of attribute
name | Name of attribute
value | Value of attribute

#### Return Value

New attribute

#### Discussion

This function adds an integer or enum attribute to an IPP message.
The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "group" argument specifies the IPP attribute group tag: none (`IPP_TAG_ZERO`, for member attributes), document (`IPP_TAG_DOCUMENT`), event notification (`IPP_TAG_EVENT_NOTIFICATION`), operation (`IPP_TAG_OPERATION`), printer (`IPP_TAG_PRINTER`), subscription (`IPP_TAG_SUBSCRIPTION`), or unsupported (`IPP_TAG_UNSUPPORTED_GROUP`).
Supported values include enum (`IPP_TAG_ENUM`) and integer (`IPP_TAG_INTEGER`).

### ippAddIntegers

Add an array of integer values.

ipp_attribute_t *ippAddIntegers(ipp_t *ipp, ipp_tag_t group, ipp_tag_t value_tag, const char *name, size_t num_values, const int *values);

#### Parameters

ipp | IPP message
group | IPP group
value_tag | Type of attribute
name | Name of attribute
num_values | Number of values
values | Values

#### Return Value

New attribute

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "group" argument specifies the IPP attribute group tag: none (`IPP_TAG_ZERO`, for member attributes), document (`IPP_TAG_DOCUMENT`), event notification (`IPP_TAG_EVENT_NOTIFICATION`), operation (`IPP_TAG_OPERATION`), printer (`IPP_TAG_PRINTER`), subscription (`IPP_TAG_SUBSCRIPTION`), or unsupported (`IPP_TAG_UNSUPPORTED_GROUP`).
Supported values include enum (`IPP_TAG_ENUM`) and integer (`IPP_TAG_INTEGER`).

### ippAddOctetString

Add an octetString value to an IPP message.

ipp_attribute_t *ippAddOctetString(ipp_t *ipp, ipp_tag_t group, const char *name, const void *data, size_t datalen);

#### Parameters

ipp | IPP message
group | IPP group
name | Name of attribute
data | octetString data
datalen | Length of data in bytes

#### Return Value

New attribute

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "group" argument specifies the IPP attribute group tag: none (`IPP_TAG_ZERO`, for member attributes), document (`IPP_TAG_DOCUMENT`), event notification (`IPP_TAG_EVENT_NOTIFICATION`), operation (`IPP_TAG_OPERATION`), printer (`IPP_TAG_PRINTER`), subscription (`IPP_TAG_SUBSCRIPTION`), or unsupported (`IPP_TAG_UNSUPPORTED_GROUP`).

### ippAddOutOfBand

Add an out-of-band value to an IPP message.

ipp_attribute_t *ippAddOutOfBand(ipp_t *ipp, ipp_tag_t group, ipp_tag_t value_tag, const char *name);

#### Parameters

ipp | IPP message
group | IPP group
value_tag | Type of attribute
name | Name of attribute

#### Return Value

New attribute

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "group" argument specifies the IPP attribute group tag: none (`IPP_TAG_ZERO`, for member attributes), document (`IPP_TAG_DOCUMENT`), event notification (`IPP_TAG_EVENT_NOTIFICATION`), operation (`IPP_TAG_OPERATION`), printer (`IPP_TAG_PRINTER`), subscription (`IPP_TAG_SUBSCRIPTION`), or unsupported (`IPP_TAG_UNSUPPORTED_GROUP`).
Supported out-of-band values include unsupported-value (`IPP_TAG_UNSUPPORTED_VALUE`), default (`IPP_TAG_DEFAULT`), unknown (`IPP_TAG_UNKNOWN`), no-value (`IPP_TAG_NOVALUE`), not-settable (`IPP_TAG_NOTSETTABLE`), delete-attribute (`IPP_TAG_DELETEATTR`), and admin-define (`IPP_TAG_ADMINDEFINE`).

### ippAddRange

Add a range of values to an IPP message.

ipp_attribute_t *ippAddRange(ipp_t *ipp, ipp_tag_t group, const char *name, int lower, int upper);

#### Parameters

ipp | IPP message
group | IPP group
name | Name of attribute
lower | Lower value
upper | Upper value

#### Return Value

New attribute

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "group" argument specifies the IPP attribute group tag: none (`IPP_TAG_ZERO`, for member attributes), document (`IPP_TAG_DOCUMENT`), event notification (`IPP_TAG_EVENT_NOTIFICATION`), operation (`IPP_TAG_OPERATION`), printer (`IPP_TAG_PRINTER`), subscription (`IPP_TAG_SUBSCRIPTION`), or unsupported (`IPP_TAG_UNSUPPORTED_GROUP`).
The "lower" argument must be less than or equal to the `upper" argument.`

### ippAddRanges

Add ranges of values to an IPP message.

ipp_attribute_t *ippAddRanges(ipp_t *ipp, ipp_tag_t group, const char *name, size_t num_values, const int *lower, const int *upper);

#### Parameters

ipp | IPP message
group | IPP group
name | Name of attribute
num_values | Number of values
lower | Lower values
upper | Upper values

#### Return Value

New attribute

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "group" argument specifies the IPP attribute group tag: none (`IPP_TAG_ZERO`, for member attributes), document (`IPP_TAG_DOCUMENT`), event notification (`IPP_TAG_EVENT_NOTIFICATION`), operation (`IPP_TAG_OPERATION`), printer (`IPP_TAG_PRINTER`), subscription (`IPP_TAG_SUBSCRIPTION`), or unsupported (`IPP_TAG_UNSUPPORTED_GROUP`).

### ippAddResolution

Add a resolution value to an IPP message.

ipp_attribute_t *ippAddResolution(ipp_t *ipp, ipp_tag_t group, const char *name, ipp_res_t units, int xres, int yres);

#### Parameters

ipp | IPP message
group | IPP group
name | Name of attribute
units | Units for resolution
xres | X resolution
yres | Y resolution

#### Return Value

New attribute

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "group" argument specifies the IPP attribute group tag: none (`IPP_TAG_ZERO`, for member attributes), document (`IPP_TAG_DOCUMENT`), event notification (`IPP_TAG_EVENT_NOTIFICATION`), operation (`IPP_TAG_OPERATION`), printer (`IPP_TAG_PRINTER`), subscription (`IPP_TAG_SUBSCRIPTION`), or unsupported (`IPP_TAG_UNSUPPORTED_GROUP`).

### ippAddResolutions

Add resolution values to an IPP message.

ipp_attribute_t *ippAddResolutions(ipp_t *ipp, ipp_tag_t group, const char *name, size_t num_values, ipp_res_t units, const int *xres, const int *yres);

#### Parameters

ipp | IPP message
group | IPP group
name | Name of attribute
num_values | Number of values
units | Units for resolution
xres | X resolutions
yres | Y resolutions

#### Return Value

New attribute

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "group" argument specifies the IPP attribute group tag: none (`IPP_TAG_ZERO`, for member attributes), document (`IPP_TAG_DOCUMENT`), event notification (`IPP_TAG_EVENT_NOTIFICATION`), operation (`IPP_TAG_OPERATION`), printer (`IPP_TAG_PRINTER`), subscription (`IPP_TAG_SUBSCRIPTION`), or unsupported (`IPP_TAG_UNSUPPORTED_GROUP`).

### ippAddSeparator

Add a group separator to an IPP message.

ipp_attribute_t *ippAddSeparator(ipp_t *ipp);

#### Parameters

ipp | IPP message

#### Return Value

New attribute

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.

### ippAddString

Add a language-encoded string to an IPP message.

ipp_attribute_t *ippAddString(ipp_t *ipp, ipp_tag_t group, ipp_tag_t value_tag, const char *name, const char *language, const char *value);

#### Parameters

ipp | IPP message
group | IPP group
value_tag | Type of attribute
name | Name of attribute
language | Language code
value | Value

#### Return Value

New attribute

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "group" argument specifies the IPP attribute group tag: none (`IPP_TAG_ZERO`, for member attributes), document (`IPP_TAG_DOCUMENT`), event notification (`IPP_TAG_EVENT_NOTIFICATION`), operation (`IPP_TAG_OPERATION`), printer (`IPP_TAG_PRINTER`), subscription (`IPP_TAG_SUBSCRIPTION`), or unsupported (`IPP_TAG_UNSUPPORTED_GROUP`).
Supported string values include charset (`IPP_TAG_CHARSET`), keyword (`IPP_TAG_KEYWORD`), language (`IPP_TAG_LANGUAGE`), mimeMediaType (`IPP_TAG_MIMETYPE`), name (`IPP_TAG_NAME`), nameWithLanguage (`IPP_TAG_NAMELANG), text (`IPP_TAG_TEXT`), textWithLanguage (`IPP_TAG_TEXTLANG`), uri (`IPP_TAG_URI`), and uriScheme (`IPP_TAG_URISCHEME`). The "language" argument must be non-`NULL` for nameWithLanguage and textWithLanguage string values and must be `NULL` for all other string values.`

### ippAddStringf

Add a formatted string to an IPP message.

ipp_attribute_t *ippAddStringf(ipp_t *ipp, ipp_tag_t group, ipp_tag_t value_tag, const char *name, const char *language, const char *format, ...);

#### Parameters

ipp | IPP message
group | IPP group
value_tag | Type of attribute
name | Name of attribute
language | Language code (`NULL` for default)
format | Printf-style format string
... | Additional arguments as needed

#### Return Value

New attribute

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "group" argument specifies the IPP attribute group tag: none (`IPP_TAG_ZERO`, for member attributes), document (`IPP_TAG_DOCUMENT`), event notification (`IPP_TAG_EVENT_NOTIFICATION`), operation (`IPP_TAG_OPERATION`), printer (`IPP_TAG_PRINTER`), subscription (`IPP_TAG_SUBSCRIPTION`), or unsupported (`IPP_TAG_UNSUPPORTED_GROUP`).
Supported string values include charset (`IPP_TAG_CHARSET`), keyword (`IPP_TAG_KEYWORD`), language (`IPP_TAG_LANGUAGE`), mimeMediaType (`IPP_TAG_MIMETYPE`), name (`IPP_TAG_NAME`), nameWithLanguage (`IPP_TAG_NAMELANG), text (`IPP_TAG_TEXT`), textWithLanguage (`IPP_TAG_TEXTLANG`), uri (`IPP_TAG_URI`), and uriScheme (`IPP_TAG_URISCHEME`). The "language" argument must be non-`NULL` for nameWithLanguage and textWithLanguage string values and must be `NULL` for all other string values. The "format" argument uses formatting characters compatible with the printf family of standard functions. Additional arguments follow it as needed. The formatted string is truncated as needed to the maximum length of the corresponding value type.`

### ippAddStringfv

Add a formatted string to an IPP message.

ipp_attribute_t *ippAddStringfv(ipp_t *ipp, ipp_tag_t group, ipp_tag_t value_tag, const char *name, const char *language, const char *format, va_list ap);

#### Parameters

ipp | IPP message
group | IPP group
value_tag | Type of attribute
name | Name of attribute
language | Language code (`NULL` for default)
format | Printf-style format string
ap | Additional arguments

#### Return Value

New attribute

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "group" argument specifies the IPP attribute group tag: none (`IPP_TAG_ZERO`, for member attributes), document (`IPP_TAG_DOCUMENT`), event notification (`IPP_TAG_EVENT_NOTIFICATION`), operation (`IPP_TAG_OPERATION`), printer (`IPP_TAG_PRINTER`), subscription (`IPP_TAG_SUBSCRIPTION`), or unsupported (`IPP_TAG_UNSUPPORTED_GROUP`).
Supported string values include charset (`IPP_TAG_CHARSET`), keyword (`IPP_TAG_KEYWORD`), language (`IPP_TAG_LANGUAGE`), mimeMediaType (`IPP_TAG_MIMETYPE`), name (`IPP_TAG_NAME`), nameWithLanguage (`IPP_TAG_NAMELANG), text (`IPP_TAG_TEXT`), textWithLanguage (`IPP_TAG_TEXTLANG`), uri (`IPP_TAG_URI`), and uriScheme (`IPP_TAG_URISCHEME`). The "language" argument must be non-`NULL` for nameWithLanguage and textWithLanguage string values and must be `NULL` for all other string values. The "format" argument uses formatting characters compatible with the printf family of standard functions. Additional arguments are passed in the stdarg pointer "ap". The formatted string is truncated as needed to the maximum length of the corresponding value type.`

### ippAddStrings

Add language-encoded strings to an IPP message.

ipp_attribute_t *ippAddStrings(ipp_t *ipp, ipp_tag_t group, ipp_tag_t value_tag, const char *name, size_t num_values, const char *language, const char *const *values);

#### Parameters

ipp | IPP message
group | IPP group
value_tag | Type of attribute
name | Name of attribute
num_values | Number of values
language | Language code (`NULL` for default)
values | Values

#### Return Value

New attribute

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "group" argument specifies the IPP attribute group tag: none (`IPP_TAG_ZERO`, for member attributes), document (`IPP_TAG_DOCUMENT`), event notification (`IPP_TAG_EVENT_NOTIFICATION`), operation (`IPP_TAG_OPERATION`), printer (`IPP_TAG_PRINTER`), subscription (`IPP_TAG_SUBSCRIPTION`), or unsupported (`IPP_TAG_UNSUPPORTED_GROUP`).
Supported string values include charset (`IPP_TAG_CHARSET`), keyword (`IPP_TAG_KEYWORD`), language (`IPP_TAG_LANGUAGE`), mimeMediaType (`IPP_TAG_MIMETYPE`), name (`IPP_TAG_NAME`), nameWithLanguage (`IPP_TAG_NAMELANG), text (`IPP_TAG_TEXT`), textWithLanguage (`IPP_TAG_TEXTLANG`), uri (`IPP_TAG_URI`), and uriScheme (`IPP_TAG_URISCHEME`). The "language" argument must be non-`NULL` for nameWithLanguage and textWithLanguage string values and must be `NULL` for all other string values.`

### ippAttributeString

Convert the attribute's value to a string.

size_t ippAttributeString(ipp_attribute_t *attr, char *buffer, size_t bufsize);

#### Parameters

attr | Attribute
buffer | String buffer or `NULL`
bufsize | Size of string buffer

#### Return Value

Number of bytes less `nul`

#### Discussion

This function converts an attribute's values into a string and returns the number of bytes that would be written, not including the trailing `nul`. The buffer pointer can be NULL to get the required length, just like `(v)snprintf`.

### ippContainsInteger

Determine whether an attribute contains the specified value or is within the list of ranges.

bool ippContainsInteger(ipp_attribute_t *attr, int value);

#### Parameters

attr | Attribute
value | Integer/enum value

#### Return Value

`true` on a match, `false` on no match

#### Discussion

This function returns `true` when the attribute contains either a matching integer or enum value, or the value falls within one of the rangeOfInteger values for the attribute.

### ippContainsString

Determine whether an attribute contains the specified string value.

bool ippContainsString(ipp_attribute_t *attr, const char *value);

#### Parameters

attr | Attribute
value | String value

#### Return Value

`true` on a match, `false` on no match

#### Discussion

This function returns `true` when the attribute contains a matching charset, keyword, naturalLanguage, mimeMediaType, name, text, uri, or uriScheme value.

### ippCopyAttribute

Copy an attribute.

ipp_attribute_t *ippCopyAttribute(ipp_t *dst, ipp_attribute_t *srcattr, bool quickcopy);

#### Parameters

dst | Destination IPP message
srcattr | Attribute to copy
quickcopy | `true` for a referenced copy, `false` for a new copy

#### Return Value

New attribute

#### Discussion

This function copies an attribute to another IPP message. When "quickcopy" is `true`, a shallow reference copy of the attribute is created - this should only be done as long as the original source IPP message will not be freed for the life of the destination.

### ippCopyAttributes

Copy attributes from one IPP message to another.

bool ippCopyAttributes(ipp_t *dst, ipp_t *src, bool quickcopy, ipp_copy_cb_t cb, void *cb_data);

#### Parameters

dst | Destination IPP message
src | Source IPP message
quickcopy | `true` for a referenced copy, `false` for a new copy
cb | Copy callback or `NULL` for none
cb_data | Callback data pointer

#### Return Value

`true` on success, `false` on error

#### Discussion

This function copies zero or more attributes from the source to the destination IPP message. When "quickcopy" is `true`, a shallow reference copy of the attribute is created - this should only be done as long as the original source IPP message will not be freed for the life of the destination.
The "cb" and "cb_data" arguments provide a generic way to "filter" the attributes that are copied - the function must return `true` to copy the attribute or `false` to skip it. The function may also choose to do a partial copy of the source attribute itself and return `false` to tell this function to skip it.

### ippCopyCredentialsString

Copy a credentials value from an IPP attribute.

char *ippCopyCredentialsString(ipp_attribute_t *attr);

#### Parameters

attr | Attribute

#### Return Value

Combined string or `NULL` on error

#### Discussion

This function concatenates the 1setOf text credential values of an attribute, separated by newlines. The returned string must be freed using the `free` function.

### ippCreateRequestedArray

Create a CUPS array of attribute names from the given requested-attributes attribute.

cups_array_t *ippCreateRequestedArray(ipp_t *request);

#### Parameters

request | IPP request

#### Return Value

CUPS array or `NULL` if all

#### Discussion

This function creates a (sorted) CUPS array of attribute names matching the list of "requested-attribute" values supplied in an IPP request. All IANA- registered values are supported in addition to the CUPS IPP extension attributes.
The "request" argument specifies the request message that was read from the client.
`NULL` is returned if all attributes should be returned. Otherwise, the result is a sorted array of attribute names, where `cupsArrayFind(array, "attribute-name")` will return a non-`NULL` pointer. The array must be freed using `cupsArrayDelete`.

### ippDateToTime

Convert from RFC 2579 Date/Time format to time in seconds.

time_t ippDateToTime(const ipp_uchar_t *date);

#### Parameters

date | RFC 2579 date info

#### Return Value

UNIX time value

### ippDelete

Delete an IPP message.

void ippDelete(ipp_t *ipp);

#### Parameters

ipp | IPP message

### ippDeleteAttribute

Delete a single attribute in an IPP message.

void ippDeleteAttribute(ipp_t *ipp, ipp_attribute_t *attr);

#### Parameters

ipp | IPP message
attr | Attribute to delete

### ippDeleteValues

Delete values in an attribute.

bool ippDeleteValues(ipp_t *ipp, ipp_attribute_t **attr, size_t element, size_t count);

#### Parameters

ipp | IPP message
attr | Attribute
element | Index of first value to delete (`0`-based)
count | Number of values to delete

#### Return Value

`true` on success, `false` on failure

#### Discussion

This function deletes one or more values in an attribute. The "element" argument specifies the first value to delete, starting at `0`. It must be less than the number of values returned by `ippGetCount`.
The "attr" argument may be modified as a result of setting the value, which will set the variable to `NULL`.
Deleting all values in an attribute deletes the attribute.

### ippEnumString

Return a string corresponding to the enum value.

const char *ippEnumString(const char *attrname, int enumvalue);

#### Parameters

attrname | Attribute name
enumvalue | Enum value

#### Return Value

Enum string

### ippEnumValue

Return the value associated with a given enum string.

int ippEnumValue(const char *attrname, const char *enumstring);

#### Parameters

attrname | Attribute name
enumstring | Enum string

#### Return Value

Enum value or `-1` if unknown

### ippErrorString

Return a name for the given status code.

const char *ippErrorString(ipp_status_t error);

#### Parameters

error | Error status

#### Return Value

Text string

### ippErrorValue

Return a status code for the given name.

ipp_status_t ippErrorValue(const char *name);

#### Parameters

name | Name

#### Return Value

IPP status code

### ippFileClose

Close an IPP data file.

bool ippFileClose(ipp_file_t *file);

#### Parameters

file | IPP data file

#### Return Value

`true` on success, `false` on error

#### Discussion

This function closes the current IPP data file. The `ipp_file_t` object can be reused for another file as needed.

### ippFileDelete

Close an IPP data file and free all memory.

bool ippFileDelete(ipp_file_t *file);

#### Parameters

file | IPP data file

#### Return Value

`true` on success, `false` on error

#### Discussion

This function closes an IPP data file, if necessary, and frees all memory associated with it.

### ippFileExpandVars

Expand IPP data file and environment variables in a string.

size_t ippFileExpandVars(ipp_file_t *file, char *dst, const char *src, size_t dstsize);

#### Parameters

file | IPP data file
dst | Destination buffer
src | Source string
dstsize | Size of destination buffer

#### Return Value

Required size for expanded variables

#### Discussion

This function expands IPP data file variables in "src" of the form "$name" or "${name}" and environment variables of the form "$ENV[name]" in the source string to the destination buffer. The destination buffer "dst" is filled up to "dstsize - 1" bytes to allow for a trailing NUL character.
The return value is the actual required size for all expansions regardless of the value of "dstsize".

### ippFileGetAttribute

Get a single named attribute from an IPP data file.

ipp_attribute_t *ippFileGetAttribute(ipp_file_t *file, const char *name, ipp_tag_t value_tag);

#### Parameters

file | IPP data file
name | Attribute name
value_tag | Value tag or `IPP_TAG_ZERO` for any

#### Return Value

Attribute or `NULL` if none

#### Discussion

This function finds the first occurence of a named attribute in the current IPP attributes in the specified data file.

### ippFileGetAttributes

Get the current set of attributes from an IPP data file.

ipp_t *ippFileGetAttributes(ipp_file_t *file);

#### Parameters

file | IPP data file

#### Return Value

IPP attributes

#### Discussion

This function gets the current set of attributes from an IPP data file.

### ippFileGetFilename

Get the filename for an IPP data file.

const char *ippFileGetFilename(ipp_file_t *file);

#### Parameters

file | IPP data file

#### Return Value

Filename

#### Discussion

This function returns the filename associated with an IPP data file.

### ippFileGetLineNumber

Get the current line number in an IPP data file.

int ippFileGetLineNumber(ipp_file_t *file);

#### Parameters

file | IPP data file

#### Return Value

Line number

#### Discussion

This function returns the current line number in an IPP data file.

### ippFileGetVar

Get the value of an IPP data file variable.

const char *ippFileGetVar(ipp_file_t *file, const char *name);

#### Parameters

file | IPP data file
name | Variable name

#### Return Value

Variable value or `NULL` if none.

#### Discussion

This function returns the value of an IPP data file variable. `NULL` is returned if the variable is not set.

### ippFileNew

Create a new IPP data file object in preparation for reading or writing.

ipp_file_t *ippFileNew(ipp_file_t *parent, ipp_fattr_cb_t attr_cb, ipp_ferror_cb_t error_cb, void *cb_data);

#### Parameters

parent | Parent data file or `NULL` for none
attr_cb | Attribute filtering callback, if any
error_cb | Error reporting callback, if any
cb_data | Callback data, if any

#### Return Value

IPP data file

#### Discussion

This function creates a new IPP data file object. If the "parent" argument is not `NULL`, all variables from the parent data file are copied to the new object.
Call the `ippFileOpen` function to open the IPP data file.

### ippFileOpen

Open an IPP data file for reading or writing.

bool ippFileOpen(ipp_file_t *file, const char *filename, const char *mode);

#### Parameters

file | IPP data file
filename | Filename to open
mode | Open mode - "r" to read and "w" to write

#### Return Value

`true` on success, `false` on error

#### Discussion

This function opens the IPP data file specified by the "filename" argument for reading ("mode" is "r") or writing ("mode" is "w").

### ippFileRead

Read an IPP data file.

bool ippFileRead(ipp_file_t *file, ipp_ftoken_cb_t token_cb, bool with_groups);

#### Parameters

file | IPP data file
token_cb | Token callback
with_groups | Read attributes with GROUP directives

#### Return Value

`true` on success, `false` on error

#### Discussion

This function reads tokens from an IPP data file, processes standard directives that define attributes and values, and passes on unknown tokens to the token callback "token_cb" for processing.
If the "with_groups" argument is `true` then the "GROUP" directive will be supported for specifying the attribute group(s) associated with any defined attributes.

### ippFileReadCollection

Read a collection from an IPP data file.

ipp_t *ippFileReadCollection(ipp_file_t *file);

#### Parameters

file | IPP data file

#### Return Value

Collection value

#### Discussion

This function reads a collection value from an IPP data file. Collection values are surrounded by curly braces ("{" and "}") and have "MEMBER" directives to define member attributes in the collection.

### ippFileReadToken

Read a token from an IPP data file.

bool ippFileReadToken(ipp_file_t *file, char *token, size_t tokensize);

#### Parameters

file | IPP data file
token | Token buffer
tokensize | Size of token buffer

#### Return Value

`true` on success, `false` on error

#### Discussion

This function reads a single token or value from an IPP data file, skipping comments and whitespace as needed.

### ippFileRestorePosition

Restore the previous position in an IPP data file.

bool ippFileRestorePosition(ipp_file_t *file);

#### Parameters

file | IPP data file

#### Return Value

`true` on success, `false` on failure

#### Discussion

This function restores the previous position in an IPP data file that is open for reading.

### ippFileSavePosition

Save the current position in an IPP data file.

bool ippFileSavePosition(ipp_file_t *file);

#### Parameters

file | IPP data file

#### Return Value

`true` on success, `false` on failure

#### Discussion

This function saves the current position in an IPP data file that is open for reading.

### ippFileSetAttributes

Set the attributes for an IPP data file.

bool ippFileSetAttributes(ipp_file_t *file, ipp_t *attrs);

#### Parameters

file | IPP data file
attrs | IPP attributes

#### Return Value

`true` on success, `false` otherwise

#### Discussion

This function sets the current set of attributes for an IPP data file, typically an empty collection created with `ippNew`.

### ippFileSetGroupTag

Set the group tag for an IPP data file.

bool ippFileSetGroupTag(ipp_file_t *file, ipp_tag_t group_tag);

#### Parameters

file | IPP data file
group_tag | Group tag

#### Return Value

`true` on success, `false` otherwise

#### Discussion

This function sets the group tag associated with attributes that are read from an IPP data file.

### ippFileSetVar

Set an IPP data file variable to a constant value.

bool ippFileSetVar(ipp_file_t *file, const char *name, const char *value);

#### Parameters

file | IPP data file
name | Variable name
value | Value

#### Return Value

`true` on success, `false` on failure

#### Discussion

This function sets an IPP data file variable to a constant value. Setting the "uri" variable also initializes the "scheme", "uriuser", "hostname", "port", and "resource" variables.

### ippFileSetVarf

Set an IPP data file variable to a formatted value.

bool ippFileSetVarf(ipp_file_t *file, const char *name, const char *value, ...);

#### Parameters

file | IPP data file
name | Variable name
value | Printf-style value
... | Additional arguments as needed

#### Return Value

`true` on success, `false` on error

#### Discussion

This function sets an IPP data file variable to a formatted value. Setting the "uri" variable also initializes the "scheme", "uriuser", "hostname", "port", and "resource" variables.

### ippFileWriteAttributes

Write an IPP message to an IPP data file.

bool ippFileWriteAttributes(ipp_file_t *file, ipp_t *ipp, bool with_groups);

#### Parameters

file | IPP data file
ipp | IPP attributes to write
with_groups | `true` to include GROUPs, `false` otherwise

#### Return Value

`true` on success, `false` on error

#### Discussion

This function writes an IPP message to an IPP data file using the attribute filter specified in the call to `ippFileOpen`. If "with_group" is `true`, "GROUP" directives are written as necessary to place the attributes in the correct groups.

### ippFileWriteComment

Write a comment to an IPP data file.

bool ippFileWriteComment(ipp_file_t *file, const char *comment, ...);

#### Parameters

file | IPP data file
comment | Printf-style comment string
... | Additional arguments as needed

#### Return Value

`true` on success, `false` on error

#### Discussion

This function writes a comment to an IPP data file. Every line in the string is prefixed with the "#" character and indented as needed.

### ippFileWriteToken

Write a token or value string to an IPP data file.

bool ippFileWriteToken(ipp_file_t *file, const char *token);

#### Parameters

file | IPP data file
token | Token/value string

#### Return Value

`true` on success, `false` on error

#### Discussion

This function writes a token or value string to an IPP data file, quoting and indenting the string as needed.

### ippFileWriteTokenf

Write a formatted token or value string to an IPP data file.

bool ippFileWriteTokenf(ipp_file_t *file, const char *token, ...);

#### Parameters

file | IPP data file
token | Printf-style token/value string
... | Additional arguments as needed

#### Return Value

`true` on success, `false` on error

#### Discussion

This function writes a formatted token or value string to an IPP data file, quoting and indenting the string as needed.

### ippFindAttribute

Find a named attribute in an IPP message.

ipp_attribute_t *ippFindAttribute(ipp_t *ipp, const char *name, ipp_tag_t type);

#### Parameters

ipp | IPP message
name | Name of attribute
type | Type of attribute

#### Return Value

Matching attribute

#### Discussion

This function finds the first occurrence of a named attribute in an IPP message. The attribute name can contain a hierarchical list of attribute and member names separated by slashes, for example "media-col/media-size".

### ippFindNextAttribute

Find the next named attribute in an IPP message.

ipp_attribute_t *ippFindNextAttribute(ipp_t *ipp, const char *name, ipp_tag_t type);

#### Parameters

ipp | IPP message
name | Name of attribute
type | Type of attribute

#### Return Value

Matching attribute

#### Discussion

This function finds the next named attribute in an IPP message. The attribute name can contain a hierarchical list of attribute and member names separated by slashes, for example "media-col/media-size".

### ippGetBoolean

Get a boolean value for an attribute.

bool ippGetBoolean(ipp_attribute_t *attr, size_t element);

#### Parameters

attr | IPP attribute
element | Value number (`0`-based)

#### Return Value

Boolean value or `false` on error

#### Discussion

The "element" argument specifies which value to get from `0` to `ippGetCount(attr) - 1`.

### ippGetCollection

Get a collection value for an attribute.

ipp_t *ippGetCollection(ipp_attribute_t *attr, size_t element);

#### Parameters

attr | IPP attribute
element | Value number (`0`-based)

#### Return Value

Collection value or `NULL` on error

#### Discussion

The "element" argument specifies which value to get from `0` to `ippGetCount(attr) - 1`.

### ippGetCount

Get the number of values in an attribute.

size_t ippGetCount(ipp_attribute_t *attr);

#### Parameters

attr | IPP attribute

#### Return Value

Number of values or 0 on error

### ippGetDate

Get a dateTime value for an attribute.

const ipp_uchar_t *ippGetDate(ipp_attribute_t *attr, size_t element);

#### Parameters

attr | IPP attribute
element | Value number (`0`-based)

#### Return Value

dateTime value or `NULL`

#### Discussion

The "element" argument specifies which value to get from `0` to `ippGetCount(attr) - 1`.

### ippGetFirstAttribute

Return the first attribute in the message.

ipp_attribute_t *ippGetFirstAttribute(ipp_t *ipp);

#### Parameters

ipp | IPP message

#### Return Value

First attribute or `NULL` if none

### ippGetGroupTag

Get the group associated with an attribute.

ipp_tag_t ippGetGroupTag(ipp_attribute_t *attr);

#### Parameters

attr | IPP attribute

#### Return Value

Group tag or `IPP_TAG_ZERO` on error

### ippGetInteger

Get the integer/enum value for an attribute.

int ippGetInteger(ipp_attribute_t *attr, size_t element);

#### Parameters

attr | IPP attribute
element | Value number (`0`-based)

#### Return Value

Value or `0` on error

#### Discussion

The "element" argument specifies which value to get from `0` to `ippGetCount(attr) - 1`.

### ippGetLength

Compute the length of an IPP message.

size_t ippGetLength(ipp_t *ipp);

#### Parameters

ipp | IPP message

#### Return Value

Size of IPP message

### ippGetName

Get the attribute name.

const char *ippGetName(ipp_attribute_t *attr);

#### Parameters

attr | IPP attribute

#### Return Value

Attribute name or `NULL` for separators

### ippGetNextAttribute

Return the next attribute in the message.

ipp_attribute_t *ippGetNextAttribute(ipp_t *ipp);

#### Parameters

ipp | IPP message

#### Return Value

Next attribute or `NULL` if none

### ippGetOctetString

Get an octetString value from an IPP attribute.

void *ippGetOctetString(ipp_attribute_t *attr, size_t element, size_t *datalen);

#### Parameters

attr | IPP attribute
element | Value number (`0`-based)
datalen | Length of octetString data

#### Return Value

Pointer to octetString data

#### Discussion

The "element" argument specifies which value to get from '0' to `ippGetCount(attr) - 1`.

### ippGetOperation

Get the operation ID in an IPP message.

ipp_op_t ippGetOperation(ipp_t *ipp);

#### Parameters

ipp | IPP request message

#### Return Value

Operation ID or 0 on error

### ippGetPort

Return the default IPP port number.

int ippGetPort(void);

#### Return Value

Port number

### ippGetRange

Get a rangeOfInteger value from an attribute.

int ippGetRange(ipp_attribute_t *attr, size_t element, int *uppervalue);

#### Parameters

attr | IPP attribute
element | Value number (`0`-based)
uppervalue | Upper value of range

#### Return Value

Lower value of range or 0

#### Discussion

The "element" argument specifies which value to get from `0` to `ippGetCount(attr) - 1`.

### ippGetRequestId

Get the request ID from an IPP message.

int ippGetRequestId(ipp_t *ipp);

#### Parameters

ipp | IPP message

#### Return Value

Request ID or 0 on error

### ippGetResolution

Get a resolution value for an attribute.

int ippGetResolution(ipp_attribute_t *attr, size_t element, int *yres, ipp_res_t *units);

#### Parameters

attr | IPP attribute
element | Value number (`0`-based)
yres | Vertical/feed resolution
units | Units for resolution

#### Return Value

Horizontal/cross feed resolution or 0

#### Discussion

The "element" argument specifies which value to get from `0` to `ippGetCount(attr) - 1`.

### ippGetState

Get the IPP message state.

ipp_state_t ippGetState(ipp_t *ipp);

#### Parameters

ipp | IPP message

#### Return Value

IPP message state value

### ippGetStatusCode

Get the status code from an IPP response or event message.

ipp_status_t ippGetStatusCode(ipp_t *ipp);

#### Parameters

ipp | IPP response or event message

#### Return Value

Status code in IPP message

### ippGetString

const char *ippGetString(ipp_attribute_t *attr, size_t element, const char **language);

#### Parameters

attr | IPP attribute
element | Value number (`0`-based)
language | Language code (`NULL` for don't care)

#### Return Value

Get the string and optionally the language code for an attribute.

The "element" argument specifies which value to get from `0` to `ippGetCount(attr) - 1`.

### ippGetValueTag

Get the value tag for an attribute.

ipp_tag_t ippGetValueTag(ipp_attribute_t *attr);

#### Parameters

attr | IPP attribute

#### Return Value

Value tag or `IPP_TAG_ZERO` on error

### ippGetVersion

Get the major and minor version number from an IPP message.

int ippGetVersion(ipp_t *ipp, int *minor);

#### Parameters

ipp | IPP message
minor | Minor version number or `NULL` for don't care

#### Return Value

Major version number or 0 on error

### ippNew

Allocate a new IPP message.

ipp_t *ippNew(void);

#### Return Value

New IPP message

### ippNewRequest

Allocate a new IPP request message.

ipp_t *ippNewRequest(ipp_op_t op);

#### Parameters

op | Operation code

#### Return Value

IPP request message

#### Discussion

The new request message is initialized with the "attributes-charset" and "attributes-natural-language" attributes added. The "attributes-natural-language" value is derived from the current locale.

### ippNewResponse

Allocate a new IPP response message.

ipp_t *ippNewResponse(ipp_t *request);

#### Parameters

request | IPP request message

#### Return Value

IPP response message

#### Discussion

The new response message is initialized with the same "version-number", "request-id", "attributes-charset", and "attributes-natural-language" as the provided request message. If the "attributes-charset" or "attributes-natural-language" attributes are missing from the request, 'utf-8' and a value derived from the current locale are substituted, respectively.

### ippOpString

Return a name for the given operation id.

const char *ippOpString(ipp_op_t op);

#### Parameters

op | Operation ID

#### Return Value

Name

### ippOpValue

Return an operation id for the given name.

ipp_op_t ippOpValue(const char *name);

#### Parameters

name | Textual name

#### Return Value

Operation ID

### ippRead

Read data for an IPP message from a HTTP connection.

ipp_state_t ippRead(http_t *http, ipp_t *ipp);

#### Parameters

http | HTTP connection
ipp | IPP data

#### Return Value

Current state

### ippReadFile

Read data for an IPP message from a file.

ipp_state_t ippReadFile(int fd, ipp_t *ipp);

#### Parameters

fd | HTTP data
ipp | IPP data

#### Return Value

Current state

### ippReadIO

Read data for an IPP message.

ipp_state_t ippReadIO(void *src, ipp_io_cb_t cb, bool blocking, ipp_t *parent, ipp_t *ipp);

#### Parameters

src | Data source
cb | Read callback function
blocking | Use blocking IO?
parent | Parent request, if any
ipp | IPP data

#### Return Value

Current state

### ippRestore

Restore a previously saved find position.

void ippRestore(ipp_t *ipp);

#### Parameters

ipp | IPP message

### ippSave

Save the current find position.

void ippSave(ipp_t *ipp);

#### Parameters

ipp | IPP message

### ippSetBoolean

Set a boolean value in an attribute.

bool ippSetBoolean(ipp_t *ipp, ipp_attribute_t **attr, size_t element, bool boolvalue);

#### Parameters

ipp | IPP message
attr | IPP attribute
element | Value number (`0`-based)
boolvalue | Boolean value

#### Return Value

`true` on success, `false` on failure

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "attr" argument may be modified as a result of setting the value.
The "element" argument specifies which value to set from `0` to `ippGetCount(attr)`.

### ippSetCollection

Set a collection value in an attribute.

bool ippSetCollection(ipp_t *ipp, ipp_attribute_t **attr, size_t element, ipp_t *colvalue);

#### Parameters

ipp | IPP message
attr | IPP attribute
element | Value number (`0`-based)
colvalue | Collection value

#### Return Value

`true` on success, `false` on failure

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "attr" argument may be modified as a result of setting the value.
The "element" argument specifies which value to set from `0` to `ippGetCount(attr)`.

### ippSetDate

Set a dateTime value in an attribute.

bool ippSetDate(ipp_t *ipp, ipp_attribute_t **attr, size_t element, const ipp_uchar_t *datevalue);

#### Parameters

ipp | IPP message
attr | IPP attribute
element | Value number (`0`-based)
datevalue | dateTime value

#### Return Value

`true` on success, `false` on failure

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "attr" argument may be modified as a result of setting the value.
The "element" argument specifies which value to set from `0` to `ippGetCount(attr)`.

### ippSetGroupTag

Set the group tag of an attribute.

bool ippSetGroupTag(ipp_t *ipp, ipp_attribute_t **attr, ipp_tag_t group_tag);

#### Parameters

ipp | IPP message
attr | Attribute
group_tag | Group tag

#### Return Value

`true` on success, `false` on failure

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "attr" argument may be modified as a result of setting the value.
The "group" argument specifies the IPP attribute group tag: none (`IPP_TAG_ZERO`, for member attributes), document (`IPP_TAG_DOCUMENT`), event notification (`IPP_TAG_EVENT_NOTIFICATION`), operation (`IPP_TAG_OPERATION`), printer (`IPP_TAG_PRINTER`), subscription (`IPP_TAG_SUBSCRIPTION`), or unsupported (`IPP_TAG_UNSUPPORTED_GROUP`).

### ippSetInteger

Set an integer or enum value in an attribute.

bool ippSetInteger(ipp_t *ipp, ipp_attribute_t **attr, size_t element, int intvalue);

#### Parameters

ipp | IPP message
attr | IPP attribute
element | Value number (`0`-based)
intvalue | Integer/enum value

#### Return Value

`true` on success, `false` on failure

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "attr" argument may be modified as a result of setting the value.
The "element" argument specifies which value to set from `0` to `ippGetCount(attr)`.

### ippSetName

Set the name of an attribute.

bool ippSetName(ipp_t *ipp, ipp_attribute_t **attr, const char *name);

#### Parameters

ipp | IPP message
attr | IPP attribute
name | Attribute name

#### Return Value

`true` on success, `false` on failure

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "attr" argument may be modified as a result of setting the value.

### ippSetOctetString

Set an octetString value in an IPP attribute.

bool ippSetOctetString(ipp_t *ipp, ipp_attribute_t **attr, size_t element, const void *data, size_t datalen);

#### Parameters

ipp | IPP message
attr | IPP attribute
element | Value number (`0`-based)
data | Pointer to octetString data
datalen | Length of octetString data

#### Return Value

`true` on success, `false` on failure

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "attr" argument may be modified as a result of setting the value.
The "element" argument specifies which value to set from `0` to `ippGetCount(attr)`.

### ippSetOperation

Set the operation ID in an IPP request message.

bool ippSetOperation(ipp_t *ipp, ipp_op_t op);

#### Parameters

ipp | IPP request message
op | Operation ID

#### Return Value

`true` on success, `false` on failure

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.

### ippSetPort

Set the default port number.

void ippSetPort(int p);

#### Parameters

p | Port number to use

### ippSetRange

Set a rangeOfInteger value in an attribute.

bool ippSetRange(ipp_t *ipp, ipp_attribute_t **attr, size_t element, int lowervalue, int uppervalue);

#### Parameters

ipp | IPP message
attr | IPP attribute
element | Value number (`0`-based)
lowervalue | Lower bound for range
uppervalue | Upper bound for range

#### Return Value

`true` on success, `false` on failure

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "attr" argument may be modified as a result of setting the value.
The "element" argument specifies which value to set from `0` to `ippGetCount(attr)`.

### ippSetRequestId

Set the request ID in an IPP message.

bool ippSetRequestId(ipp_t *ipp, int request_id);

#### Parameters

ipp | IPP message
request_id | Request ID

#### Return Value

`true` on success, `false` on failure

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "request_id" argument must be greater than 0.

### ippSetResolution

Set a resolution value in an attribute.

bool ippSetResolution(ipp_t *ipp, ipp_attribute_t **attr, size_t element, ipp_res_t unitsvalue, int xresvalue, int yresvalue);

#### Parameters

ipp | IPP message
attr | IPP attribute
element | Value number (`0`-based)
unitsvalue | Resolution units
xresvalue | Horizontal/cross feed resolution
yresvalue | Vertical/feed resolution

#### Return Value

`true` on success, `false` on failure

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "attr" argument may be modified as a result of setting the value.
The "element" argument specifies which value to set from `0` to `ippGetCount(attr)`.

### ippSetState

Set the current state of the IPP message.

bool ippSetState(ipp_t *ipp, ipp_state_t state);

#### Parameters

ipp | IPP message
state | IPP state value

#### Return Value

`true` on success, `false` on failure

### ippSetStatusCode

Set the status code in an IPP response or event message.

bool ippSetStatusCode(ipp_t *ipp, ipp_status_t status);

#### Parameters

ipp | IPP response or event message
status | Status code

#### Return Value

`true` on success, `false` on failure

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.

### ippSetString

Set a string value in an attribute.

bool ippSetString(ipp_t *ipp, ipp_attribute_t **attr, size_t element, const char *strvalue);

#### Parameters

ipp | IPP message
attr | IPP attribute
element | Value number (`0`-based)
strvalue | String value

#### Return Value

`true` on success, `false` on failure

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "attr" argument may be modified as a result of setting the value.
The "element" argument specifies which value to set from `0` to `ippGetCount(attr)`.

### ippSetStringf

Set a formatted string value of an attribute.

bool ippSetStringf(ipp_t *ipp, ipp_attribute_t **attr, size_t element, const char *format, ...);

#### Parameters

ipp | IPP message
attr | IPP attribute
element | Value number (`0`-based)
format | Printf-style format string
... | Additional arguments as needed

#### Return Value

`true` on success, `false` on failure

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "attr" argument may be modified as a result of setting the value.
The "element" argument specifies which value to set from `0` to `ippGetCount(attr)`.
The "format" argument uses formatting characters compatible with the printf family of standard functions. Additional arguments follow it as needed. The formatted string is truncated as needed to the maximum length of the corresponding value type.

### ippSetStringfv

Set a formatted string value of an attribute.

bool ippSetStringfv(ipp_t *ipp, ipp_attribute_t **attr, size_t element, const char *format, va_list ap);

#### Parameters

ipp | IPP message
attr | IPP attribute
element | Value number (`0`-based)
format | Printf-style format string
ap | Pointer to additional arguments

#### Return Value

`true` on success, `false` on failure

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "attr" argument may be modified as a result of setting the value.
The "element" argument specifies which value to set from `0` to `ippGetCount(attr)`.
The "format" argument uses formatting characters compatible with the printf family of standard functions. Additional arguments follow it as needed. The formatted string is truncated as needed to the maximum length of the corresponding value type.

### ippSetValueTag

Set the value tag of an attribute.

bool ippSetValueTag(ipp_t *ipp, ipp_attribute_t **attr, ipp_tag_t value_tag);

#### Parameters

ipp | IPP message
attr | IPP attribute
value_tag | Value tag

#### Return Value

`true` on success, `false` on failure

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The "attr" argument may be modified as a result of setting the value.
Integer (`IPP_TAG_INTEGER`) values can be promoted to rangeOfInteger (`IPP_TAG_RANGE`) values, the various string tags can be promoted to name (`IPP_TAG_NAME`) or nameWithLanguage (`IPP_TAG_NAMELANG`) values, text (`IPP_TAG_TEXT`) values can be promoted to textWithLanguage (`IPP_TAG_TEXTLANG`) values, and all values can be demoted to the various out-of-band value tags such as no-value (`IPP_TAG_NOVALUE`). All other changes will be rejected.
Promoting a string attribute to nameWithLanguage or textWithLanguage adds the language code in the "attributes-natural-language" attribute or, if not present, the language code for the current locale.

### ippSetVersion

Set the version number in an IPP message.

bool ippSetVersion(ipp_t *ipp, int major, int minor);

#### Parameters

ipp | IPP message
major | Major version number (major.minor)
minor | Minor version number (major.minor)

#### Return Value

`true` on success, `false` on failure

#### Discussion

The "ipp" argument refers to an IPP message previously created using the `ippNew`, `ippNewRequest`, or `ippNewResponse` functions.
The valid version numbers are currently 1.0, 1.1, 2.0, 2.1, and 2.2.

### ippStateString

Return the name corresponding to a state value.

const char *ippStateString(ipp_state_t state);

#### Parameters

state | State value

#### Return Value

State name

### ippTagString

Return the tag name corresponding to a tag value.

const char *ippTagString(ipp_tag_t tag);

#### Parameters

tag | Tag value

#### Return Value

Tag name

#### Discussion

The returned names are defined in RFC 8011 and the IANA IPP Registry.

### ippTagValue

Return the tag value corresponding to a tag name.

ipp_tag_t ippTagValue(const char *name);

#### Parameters

name | Tag name

#### Return Value

Tag value

#### Discussion

The tag names are defined in RFC 8011 and the IANA IPP Registry.

### ippTimeToDate

Convert from time in seconds to RFC 2579 format.

const ipp_uchar_t *ippTimeToDate(time_t t);

#### Parameters

t | Time in seconds

#### Return Value

RFC-2579 date/time data

### ippValidateAttribute

Validate the contents of an attribute.

bool ippValidateAttribute(ipp_attribute_t *attr);

#### Parameters

attr | Attribute

#### Return Value

`true` if valid, `false` otherwise

#### Discussion

This function validates the contents of an attribute based on the name and value tag. `true` is returned if the attribute is valid, `false` otherwise. On failure, `cupsGetErrorString` is set to a human-readable message.

### ippValidateAttributes

Validate all attributes in an IPP message.

bool ippValidateAttributes(ipp_t *ipp);

#### Parameters

ipp | IPP message

#### Return Value

`true` if valid, `false` otherwise

#### Discussion

This function validates the contents of the IPP message, including each attribute. Like `ippValidateAttribute`, `cupsGetErrorString` is set to a human-readable message on failure.

### ippWrite

Write data for an IPP message to a HTTP connection.

ipp_state_t ippWrite(http_t *http, ipp_t *ipp);

#### Parameters

http | HTTP connection
ipp | IPP data

#### Return Value

Current state

### ippWriteFile

Write data for an IPP message to a file.

ipp_state_t ippWriteFile(int fd, ipp_t *ipp);

#### Parameters

fd | HTTP data
ipp | IPP data

#### Return Value

Current state

### ippWriteIO

Write data for an IPP message.

ipp_state_t ippWriteIO(void *dst, ipp_io_cb_t cb, bool blocking, ipp_t *parent, ipp_t *ipp);

#### Parameters

dst | Destination
cb | Write callback function
blocking | Use blocking IO?
parent | Parent IPP message
ipp | IPP data

#### Return Value

Current state

### pwgFormatSizeName

Generate a PWG self-describing media size name.

bool pwgFormatSizeName(char *keyword, size_t keysize, const char *prefix, const char *name, int width, int length, const char *units);

#### Parameters

keyword | Keyword buffer
keysize | Size of keyword buffer
prefix | Prefix for PWG size or `NULL` for automatic
name | Size name or `NULL`
width | Width of page in 2540ths
length | Length of page in 2540ths
units | Units - "in", "mm", or `NULL` for automatic

#### Return Value

`true` on success, `false` on failure

#### Discussion

This function generates a PWG self-describing media size name of the form "prefix_name_WIDTHxLENGTHunits". The prefix is typically "custom" or "roll" for user-supplied sizes but can also be "disc", "iso", "jis", "jpn", "na", "oe", "om", "prc", or "roc". A value of `NULL` automatically chooses "oe" or "om" depending on the units.
The size name may only contain lowercase letters, numbers, "-", and ".". If `NULL` is passed, the size name will contain the formatted dimensions.
The width and length are specified in hundredths of millimeters, equivalent to 1/100000th of a meter or 1/2540th of an inch. The width, length, and units used for the generated size name are calculated automatically if the units string is `NULL`, otherwise inches ("in") or millimeters ("mm") are used.

### pwgInitSize

Initialize a pwg_size_t structure using IPP Job Template attributes.

bool pwgInitSize(pwg_size_t *size, ipp_t *job, bool *margins_set);

#### Parameters

size | Size to initialize
job | Job template attributes
margins_set | `true` if margins were set, `false` otherwise

#### Return Value

`true` on success, `false` on failure

#### Discussion

This function initializes a pwg_size_t structure from an IPP "media" or "media-col" attribute in the specified IPP message. 0 is returned if neither attribute is found in the message or the values are not valid.
The "margins_set" variable is initialized to 1 if any "media-xxx-margin" member attribute was specified in the "media-col" Job Template attribute, otherwise it is initialized to 0.

### pwgMediaForLegacy

Find a PWG media size by ISO/IPP legacy name.

pwg_media_t *pwgMediaForLegacy(const char *legacy);

#### Parameters

legacy | Legacy size name

#### Return Value

Matching size or NULL

#### Discussion

The "name" argument specifies the legacy ISO media size name, for example "iso-a4" or "na-letter".

### pwgMediaForPPD

Find a PWG media size by Adobe PPD name.

pwg_media_t *pwgMediaForPPD(const char *ppd);

#### Parameters

ppd | PPD size name

#### Return Value

Matching size or NULL

#### Discussion

The "ppd" argument specifies an Adobe page size name as defined in Table B.1 of the Adobe PostScript Printer Description File Format Specification Version 4.3.
If the name is non-standard, the returned PWG media size is stored in thread-local storage and is overwritten by each call to the function in the thread. Custom names can be of the form "Custom.WIDTHxLENGTH[units]" or "WIDTHxLENGTH[units]".

### pwgMediaForPWG

Find a PWG media size by 5101.1 self-describing name.

pwg_media_t *pwgMediaForPWG(const char *pwg);

#### Parameters

pwg | PWG size name

#### Return Value

Matching size or NULL

#### Discussion

The "pwg" argument specifies a self-describing media size name of the form "prefix_name_WIDTHxLENGTHunits" as defined in PWG 5101.1.
If the name is non-standard, the returned PWG media size is stored in thread-local storage and is overwritten by each call to the function in the thread.

### pwgMediaForSize

Get the PWG media size for the given dimensions.

pwg_media_t *pwgMediaForSize(int width, int length);

#### Parameters

width | Width in hundredths of millimeters
length | Length in hundredths of millimeters

#### Return Value

PWG media name

#### Discussion

The "width" and "length" are in hundredths of millimeters, equivalent to 1/100000th of a meter or 1/2540th of an inch.
If the dimensions are non-standard, the returned PWG media size is stored in thread-local storage and is overwritten by each call to the function in the thread.

## Data Types

### cups_acopy_cb_t

Array element copy function

typedef void *(*)(void *element, void *data)cups_acopy_cb_t;

### cups_adv_t

AdvanceMedia attribute values

typedef enum cups_adv_e cups_adv_t;

### cups_afree_cb_t

Array element free function

typedef void(*)(void *element, void *data)cups_afree_cb_t;

### cups_ahash_cb_t

Array hash function

typedef size_t(*)(void *element, void *data)cups_ahash_cb_t;

### cups_array_cb_t

Array comparison function

typedef int(*)(void *first, void *second, void *data)cups_array_cb_t;

### cups_array_t

CUPS array type

typedef struct _cups_array_s cups_array_t;

### cups_bool_t

Boolean type

typedef enum cups_bool_e cups_bool_t;

### cups_cert_san_cb_t

Certificate signing subjectAltName callback

typedef bool(*)(const char *common_name, const char *subject_alt_name, void *user_data)cups_cert_san_cb_t;

### cups_cond_t

Condition variable

typedef pthread_cond_t cups_cond_t;

### cups_credpurpose_t

Combined X.509 credential purposes for `cupsCreateCredentials` and `cupsCreateCredentialsRequest`

typedef unsigned cups_credpurpose_t;

### cups_credtype_t

X.509 credential types for `cupsCreateCredentials` and `cupsCreateCredentialsRequest`

typedef enum cups_credtype_e cups_credtype_t;

### cups_credusage_t

Combined X.509 keyUsage flags for `cupsCreateCredentials` and `cupsCreateCredentialsRequest`

typedef unsigned cups_credusage_t;

### cups_cspace_t

cupsColorSpace attribute values

typedef enum cups_cspace_e cups_cspace_t;

### cups_cut_t

CutMedia attribute values

typedef enum cups_cut_e cups_cut_t;

### cups_dentry_t

Directory entry type

typedef struct cups_dentry_s cups_dentry_t;

### cups_dest_cb_t

Destination enumeration callback

typedef bool(*)(void *user_data, cups_dest_flags_t flags, cups_dest_t *dest)cups_dest_cb_t;

### cups_dest_flags_t

Combined flags for `cupsConnectDest` and `cupsEnumDests`

typedef unsigned cups_dest_flags_t;

### cups_dest_t

Destination

typedef struct cups_dest_s cups_dest_t;

### cups_dinfo_t

Destination capability and status information

typedef struct _cups_dinfo_s cups_dinfo_t;

### cups_dir_t

Directory type

typedef struct _cups_dir_s cups_dir_t;

### cups_dnssd_browse_cb_t

DNS-SD browse callback

typedef void(*)(cups_dnssd_browse_t *browse, void *cb_data, cups_dnssd_flags_t flags, uint32_t if_index, const char *name, const char *regtype, const char *domain)cups_dnssd_browse_cb_t;

### cups_dnssd_error_cb_t

DNS-SD error callback

typedef void(*)(void *cb_data, const char *message)cups_dnssd_error_cb_t;

### cups_dnssd_flags_t

DNS-SD callback flag bitmask

typedef unsigned cups_dnssd_flags_t;

### cups_dnssd_query_cb_t

DNS-SD query callback

typedef void(*)(cups_dnssd_query_t *query, void *cb_data, cups_dnssd_flags_t flags, uint32_t if_index, const char *fullname, uint16_t rrtype, const void *qdata, uint16_t qlen) cups_dnssd_query_cb_t;

### cups_dnssd_query_t

DNS query request

typedef struct _cups_dnssd_query_s cups_dnssd_query_t;

### cups_dnssd_resolve_cb_t

DNS-SD resolve callback

typedef void(*)(cups_dnssd_resolve_t *res, void *cb_data, cups_dnssd_flags_t flags, uint32_t if_index, const char *fullname, const char *host, uint16_t port, size_t num_txt, cups_option_t *txt)cups_dnssd_resolve_cb_t;

### cups_dnssd_resolve_t

DNS resolve request

typedef struct _cups_dnssd_resolve_s cups_dnssd_resolve_t;

### cups_dnssd_browse_t

DNS record type values

typedef typedef struct _cups_dnssd_browse_s cups_dnssd_browse_t;

### cups_dnssd_service_cb_t

DNS-SD service registration callback

typedef void(*)(cups_dnssd_service_t *service, void *cb_data, cups_dnssd_flags_t flags) cups_dnssd_service_cb_t;

### cups_dnssd_service_t

DNS service registration

typedef struct _cups_dnssd_service_s cups_dnssd_service_t;

### cups_dnssd_t

DNS-SD context

typedef struct _cups_dnssd_s cups_dnssd_t;

### cups_edge_t

LeadingEdge attribute values

typedef enum cups_edge_e cups_edge_t;

### cups_utf32_t

Language Encodings

typedef typedef unsigned long cups_utf32_t;

### cups_file_t

CUPS file type

typedef struct _cups_file_s cups_file_t;

### cups_job_t

Job information

typedef struct cups_job_s cups_job_t;

### cups_jog_t

Jog attribute values

typedef enum cups_jog_e cups_jog_t;

### cups_json_t

JSON node

typedef struct _cups_json_s cups_json_t;

### cups_jtype_t

JSON node type

typedef enum cups_jtype_e cups_jtype_t;

### cups_jwa_t

JSON Web Algorithms

typedef enum cups_jwa_e cups_jwa_t;

### cups_jws_format_t

JSON Web Signature Formats

typedef enum cups_jws_format_e cups_jws_format_t;

### cups_jwt_t

JSON Web Token

typedef struct _cups_jwt_s cups_jwt_t;

### cups_lang_t

Language Cache

typedef struct _cups_lang_s cups_lang_t;

### cups_media_flags_t

Combined flags for `cupsGetDestMediaByName` and `cupsGetDestMediaBySize`

typedef unsigned cups_media_flags_t;

### cups_media_t

Media information

typedef struct cups_media_s cups_media_t;

### cups_mediapos_t

MediaPosition values

typedef enum cups_mediapos_e cups_mediapos_t;

### cups_mutex_t

Mutual exclusion lock

typedef pthread_mutex_t cups_mutex_t;

### cups_oauth_cb_t

OAuth callback

typedef const char *(*)(http_t *http, const char *realm, const char *scope, const char *resource, void *cb_data)cups_oauth_cb_t;

### cups_ogrant_t

OAuth Grant Types

typedef enum cups_ogrant_e cups_ogrant_t;

### cups_option_t

Printer Options

typedef struct cups_option_s cups_option_t;

### cups_order_t

cupsColorOrder attribute values

typedef enum cups_order_e cups_order_t;

### cups_orient_t

Orientation attribute values

typedef enum cups_orient_e cups_orient_t;

### cups_page_header_t

Version 2 page header

typedef struct cups_page_header_s cups_page_header_t;

### cups_password_cb_t

New password callback

typedef const char *(*)(const char *prompt, http_t *http, const char *method, const char *resource, void *cb_data)cups_password_cb_t;

### cups_ptype_t

Combined printer type/capability flags

typedef unsigned cups_ptype_t;

### cups_raster_mode_t

cupsRasterOpen modes

typedef enum cups_raster_mode_e cups_raster_mode_t;

### cups_raster_t

Raster stream data

typedef struct _cups_raster_s cups_raster_t;

### cups_rwlock_t

Reader/writer lock

typedef pthread_rwlock_t cups_rwlock_t;

### cups_thread_func_t

Thread function

typedef void *(*)(void *arg)cups_thread_func_t;

### cups_thread_key_t

Thread data key

typedef pthread_key_t cups_thread_key_t;

### cups_thread_t

Thread identifier

typedef pthread_t cups_thread_t;

### cups_whichjobs_t

Which jobs for `cupsGetJobs`

typedef enum cups_whichjobs_e cups_whichjobs_t;

### http_addr_t

Socket address union

typedef union _http_addr_u http_addr_t;

### http_addrlist_t

Socket address list, which is used to enumerate all of the addresses that are associated with a hostname.

typedef struct http_addrlist_s http_addrlist_t;

### http_encoding_t

HTTP transfer encoding values

typedef enum http_encoding_e http_encoding_t;

### http_encryption_t

HTTP encryption values

typedef enum http_encryption_e http_encryption_t;

### http_field_t

HTTP field names

typedef enum http_field_e http_field_t;

### http_keepalive_t

HTTP keep-alive values

typedef enum http_keepalive_e http_keepalive_t;

### http_resolve_cb_t

`httpResolveURI` callback

typedef bool(*)(void *data)http_resolve_cb_t;

### http_resolve_t

`httpResolveURI` options bitfield

typedef unsigned http_resolve_t;

### http_state_t

HTTP state values; states are server-oriented...

typedef enum http_state_e http_state_t;

### http_status_t

HTTP status codes

typedef enum http_status_e http_status_t;

### http_t

HTTP connection type

typedef struct _http_s http_t;

### http_timeout_cb_t

HTTP timeout callback

typedef bool(*)(http_t *http, void *user_data)http_timeout_cb_t;

### http_trust_t

Level of trust for credentials

typedef enum http_trust_e http_trust_t;

### http_uri_coding_t

URI en/decode flags

typedef enum http_uri_coding_e http_uri_coding_t;

### http_uri_status_t

URI separation status

typedef enum http_uri_status_e http_uri_status_t;

### http_version_t

HTTP version numbers

typedef enum http_version_e http_version_t;

### ipp_attribute_t

IPP attribute

typedef struct _ipp_attribute_s ipp_attribute_t;

### ipp_copy_cb_t

ippCopyAttributes callback function

typedef bool(*)(void *context, ipp_t *dst, ipp_attribute_t *attr)ipp_copy_cb_t;

### ipp_dstate_t

"document-state" values

typedef enum ipp_dstate_e ipp_dstate_t;

### ipp_fattr_cb_t

IPP data file attribute callback

typedef bool(*)(ipp_file_t *file, void *cb_data, const char *name)ipp_fattr_cb_t;

### ipp_ferror_cb_t

IPP data file error callback

typedef bool(*)(ipp_file_t *file, void *cb_data, const char *error)ipp_ferror_cb_t;

### ipp_file_t

IPP data file

typedef struct _ipp_file_s ipp_file_t;

### ipp_ftoken_cb_t

IPP data file token callback

typedef bool(*)(ipp_file_t *file, void *cb_data, const char *token)ipp_ftoken_cb_t;

### ipp_io_cb_t

ippReadIO/ippWriteIO callback function

typedef ssize_t(*)(void *context, ipp_uchar_t *buffer, size_t bytes) ipp_io_cb_t;

### ipp_jstate_t

"job-state" values

typedef enum ipp_jstate_e ipp_jstate_t;

### ipp_op_t

IPP operations

typedef enum ipp_op_e ipp_op_t;

### ipp_orient_t

"orientation-requested" values

typedef enum ipp_orient_e ipp_orient_t;

### ipp_pstate_t

"printer-state" values

typedef enum ipp_pstate_e ipp_pstate_t;

### ipp_quality_t

"print-quality" values

typedef enum ipp_quality_e ipp_quality_t;

### ipp_res_t

Resolution units

typedef enum ipp_res_e ipp_res_t;

### ipp_rstate_t

"resource-state" values

typedef enum ipp_rstate_e ipp_rstate_t;

### ipp_sstate_t

"system-state" values

typedef enum ipp_sstate_e ipp_sstate_t;

### ipp_state_t

`ipp_t` state values

typedef enum ipp_state_e ipp_state_t;

### ipp_t

IPP request/response data

typedef struct _ipp_s ipp_t;

### ipp_uchar_t

Unsigned 8-bit integer/character

typedef unsigned char ipp_uchar_t;

### pwg_media_t

Common media size data

typedef struct pwg_media_s pwg_media_t;

## Structures

### cups_dentry_s

Directory entry type

struct cups_dentry_s {
struct stat fileinfo;
char filename[260];
};

#### Members

fileinfo | File information
filename[260] | File name

### cups_dest_s

Destination

struct cups_dest_s {
char *name, *instance;
bool is_default;
size_t num_options;
cups_option_t *options;
};

#### Members

instance | Local instance name or `NULL`
is_default | Is this printer the default?
num_options | Number of options
options | Options

### cups_job_s

Job information

struct cups_job_s {
time_t completed_time;
time_t creation_time;
char *dest;
char *format;
int id;
int priority;
time_t processing_time;
int size;
ipp_jstate_t state;
char *title;
char *user;
};

#### Members

completed_time | Time the job was completed
creation_time | Time the job was created
dest | Printer or class name
format | Document format
id | The job ID
priority | Priority (1-100)
processing_time | Time the job was processed
size | Size in kilobytes
state | Job state
title | Title/job name
user | User that submitted the job

### cups_media_s

Media information

struct cups_media_s {
int width, length, bottom, left, right, top;
char media[128], color[128], source[128], type[128];
};

#### Members

top | Top margin in hundredths of millimeters
type[128] | Media type (blank for any/auto)

### cups_option_s

Printer Options

struct cups_option_s {
char *name;
char *value;
};

#### Members

name | Name of option
value | Value of option

### cups_page_header_s

Version 2 page header

struct cups_page_header_s {
unsigned AdvanceDistance;
cups_adv_t AdvanceMedia;
cups_bool_t Collate;
cups_cut_t CutMedia;
cups_bool_t Duplex;
unsigned HWResolution[2];
unsigned ImagingBoundingBox[4];
cups_bool_t InsertSheet;
cups_jog_t Jog;
cups_edge_t LeadingEdge;
cups_bool_t ManualFeed;
unsigned Margins[2];
char MediaClass[64];
char MediaColor[64];
unsigned MediaPosition;
char MediaType[64];
unsigned MediaWeight;
cups_bool_t MirrorPrint;
cups_bool_t NegativePrint;
unsigned NumCopies;
cups_orient_t Orientation;
cups_bool_t OutputFaceUp;
char OutputType[64];
unsigned PageSize[2];
cups_bool_t Separations;
cups_bool_t TraySwitch;
cups_bool_t Tumble;
unsigned cupsBitsPerColor;
unsigned cupsBitsPerPixel;
float cupsBorderlessScalingFactor;
unsigned cupsBytesPerLine;
cups_order_t cupsColorOrder;
cups_cspace_t cupsColorSpace;
unsigned cupsCompression;
unsigned cupsHeight;
float cupsImagingBBox[4];
unsigned cupsInteger[16];
char cupsMarkerType[64];
unsigned cupsMediaType;
unsigned cupsNumColors;
char cupsPageSizeName[64];
float cupsPageSize[2];
float cupsReal[16];
char cupsRenderingIntent[64];
unsigned cupsRowCount;
unsigned cupsRowFeed;
unsigned cupsRowStep;
char cupsString[16][64];
unsigned cupsWidth;
};

#### Members

AdvanceDistance | AdvanceDistance value in points
AdvanceMedia | AdvanceMedia value (`cups_adv_t`)
Collate | Collated copies value
CutMedia | CutMedia value (`cups_cut_t`)
Duplex | Duplexed (double-sided) value
HWResolution[2] | Resolution in dots-per-inch
ImagingBoundingBox[4] | Pixel region that is painted (points, left, bottom, right, top)
InsertSheet | InsertSheet value
Jog | Jog value (`cups_jog_t`)
LeadingEdge | LeadingEdge value (`cups_edge_t`)
ManualFeed | ManualFeed value
Margins[2] | Lower-lefthand margins in points
MediaClass[64] | MediaClass string
MediaColor[64] | MediaColor string
MediaPosition | MediaPosition value
MediaType[64] | MediaType string
MediaWeight | MediaWeight value in grams/m^2
MirrorPrint | MirrorPrint value
NegativePrint | NegativePrint value
NumCopies | Number of copies to produce
Orientation | Orientation value (`cups_orient_t`)
OutputFaceUp | OutputFaceUp value
OutputType[64] | OutputType string
PageSize[2] | Width and length of page in points
Separations | Separations value
TraySwitch | TraySwitch value
Tumble | Tumble value
cupsBitsPerColor | Number of bits for each color
cupsBitsPerPixel | Number of bits for each pixel
cupsBorderlessScalingFactor | Scaling that was applied to page data
cupsBytesPerLine | Number of bytes per line
cupsColorOrder | Order of colors
cupsColorSpace | True colorspace
cupsCompression | Device compression to use
cupsHeight | Height of page image in pixels
cupsImagingBBox[4] | Floating point ImagingBoundingBox (scaling factor not applied, left, bottom, right, top)
cupsInteger[16] | User-defined integer values
cupsMarkerType[64] | Ink/toner type
cupsMediaType | Media type code
cupsNumColors | Number of color compoents
cupsPageSizeName[64] | PageSize name
cupsPageSize[2] | Floating point PageSize (scaling * factor not applied)
cupsReal[16] | User-defined floating-point values
cupsRenderingIntent[64] | Color rendering intent
cupsRowCount | Rows per band
cupsRowFeed | Feed between bands
cupsRowStep | Spacing between lines
cupsString[16][64] | User-defined string values
cupsWidth | Width of page image in pixels

### http_addrlist_s

Socket address list, which is used to enumerate all of the addresses that are associated with a hostname.

struct http_addrlist_s {
http_addr_t addr;
struct http_addrlist_s *next;
};

#### Members

addr | Address
next | Pointer to next address in list

### pwg_media_s

Common media size data

struct pwg_media_s {
int width, length;
const char *pwg, *legacy, *ppd;
};

#### Members

length | Length in 2540ths
ppd | Standard Adobe PPD name

## Constants

### cups_adv_e

AdvanceMedia attribute values

#### Constants

CUPS_ADVANCE_FILE | Advance the roll after this file
CUPS_ADVANCE_JOB | Advance the roll after this job
CUPS_ADVANCE_NONE | Never advance the roll
CUPS_ADVANCE_PAGE | Advance the roll after this page
CUPS_ADVANCE_SET | Advance the roll after this set

### cups_bool_e

Boolean type

#### Constants

CUPS_FALSE | Logical false
CUPS_TRUE | Logical true

### cups_credpurpose_e

X.509 credential purposes

#### Constants

CUPS_CREDPURPOSE_ALL | All purposes
CUPS_CREDPURPOSE_CLIENT_AUTH | clientAuth
CUPS_CREDPURPOSE_CODE_SIGNING | codeSigning
CUPS_CREDPURPOSE_EMAIL_PROTECTION | emailProtection
CUPS_CREDPURPOSE_OCSP_SIGNING | OCSPSigning
CUPS_CREDPURPOSE_SERVER_AUTH | serverAuth
CUPS_CREDPURPOSE_TIME_STAMPING | timeStamping

### cups_credtype_e

X.509 credential types for `cupsCreateCredentials` and `cupsCreateCredentialsRequest`

#### Constants

CUPS_CREDTYPE_DEFAULT | Default type
CUPS_CREDTYPE_ECDSA_P256_SHA256 | ECDSA using the P-256 curve with SHA-256 hash
CUPS_CREDTYPE_ECDSA_P384_SHA256 | ECDSA using the P-384 curve with SHA-256 hash
CUPS_CREDTYPE_ECDSA_P521_SHA256 | ECDSA using the P-521 curve with SHA-256 hash
CUPS_CREDTYPE_RSA_2048_SHA256 | RSA with 2048-bit keys and SHA-256 hash
CUPS_CREDTYPE_RSA_3072_SHA256 | RSA with 3072-bit keys and SHA-256 hash
CUPS_CREDTYPE_RSA_4096_SHA256 | RSA with 4096-bit keys and SHA-256 hash

### cups_credusage_e

X.509 keyUsage flags

#### Constants

CUPS_CREDUSAGE_ALL | All keyUsage flags
CUPS_CREDUSAGE_CRL_SIGN | cRLSign
CUPS_CREDUSAGE_DATA_ENCIPHERMENT | dataEncipherment
CUPS_CREDUSAGE_DECIPHER_ONLY | decipherOnly
CUPS_CREDUSAGE_DEFAULT_CA | Defaults for CA certs
CUPS_CREDUSAGE_DEFAULT_TLS | Defaults for TLS certs
CUPS_CREDUSAGE_DIGITAL_SIGNATURE | digitalSignature
CUPS_CREDUSAGE_ENCIPHER_ONLY | encipherOnly
CUPS_CREDUSAGE_KEY_AGREEMENT | keyAgreement
CUPS_CREDUSAGE_KEY_CERT_SIGN | keyCertSign
CUPS_CREDUSAGE_KEY_ENCIPHERMENT | keyEncipherment
CUPS_CREDUSAGE_NON_REPUDIATION | nonRepudiation/contentCommitment

### cups_cspace_e

cupsColorSpace attribute values

#### Constants

CUPS_CSPACE_ADOBERGB | Red, green, blue (Adobe RGB)
CUPS_CSPACE_CIELab | CIE Lab
CUPS_CSPACE_CIEXYZ | CIE XYZ
CUPS_CSPACE_CMY | Cyan, magenta, yellow (DeviceCMY)
CUPS_CSPACE_CMYK | Cyan, magenta, yellow, black (DeviceCMYK)
CUPS_CSPACE_DEVICE1 | DeviceN, 1 color
CUPS_CSPACE_DEVICE2 | DeviceN, 2 colors
CUPS_CSPACE_DEVICE3 | DeviceN, 3 colors
CUPS_CSPACE_DEVICE4 | DeviceN, 4 colors
CUPS_CSPACE_DEVICE5 | DeviceN, 5 colors
CUPS_CSPACE_DEVICE6 | DeviceN, 6 colors
CUPS_CSPACE_DEVICE7 | DeviceN, 7 colors
CUPS_CSPACE_DEVICE8 | DeviceN, 8 colors
CUPS_CSPACE_DEVICE9 | DeviceN, 9 colors
CUPS_CSPACE_DEVICEA | DeviceN, 10 colors
CUPS_CSPACE_DEVICEB | DeviceN, 11 colors
CUPS_CSPACE_DEVICEC | DeviceN, 12 colors
CUPS_CSPACE_DEVICED | DeviceN, 13 colors
CUPS_CSPACE_DEVICEE | DeviceN, 14 colors
CUPS_CSPACE_DEVICEF | DeviceN, 15 colors
CUPS_CSPACE_GMCK DEPRECATED | Gold, magenta, yellow, black
CUPS_CSPACE_GMCS DEPRECATED | Gold, magenta, yellow, silver
CUPS_CSPACE_GOLD DEPRECATED | Gold foil
CUPS_CSPACE_ICC1 | ICC-based, 1 color
CUPS_CSPACE_ICC2 | ICC-based, 2 colors
CUPS_CSPACE_ICC3 | ICC-based, 3 colors
CUPS_CSPACE_ICC4 | ICC-based, 4 colors
CUPS_CSPACE_ICC5 | ICC-based, 5 colors
CUPS_CSPACE_ICC6 | ICC-based, 6 colors
CUPS_CSPACE_ICC7 | ICC-based, 7 colors
CUPS_CSPACE_ICC8 | ICC-based, 8 colors
CUPS_CSPACE_ICC9 | ICC-based, 9 colors
CUPS_CSPACE_ICCA | ICC-based, 10 colors
CUPS_CSPACE_ICCB | ICC-based, 11 colors
CUPS_CSPACE_ICCC | ICC-based, 12 colors
CUPS_CSPACE_ICCD | ICC-based, 13 colors
CUPS_CSPACE_ICCE | ICC-based, 14 colors
CUPS_CSPACE_ICCF | ICC-based, 15 colors
CUPS_CSPACE_K | Black (DeviceK)
CUPS_CSPACE_KCMY DEPRECATED | Black, cyan, magenta, yellow
CUPS_CSPACE_KCMYcm DEPRECATED | Black, cyan, magenta, yellow, light-cyan, light-magenta
CUPS_CSPACE_RGB | Red, green, blue (DeviceRGB, sRGB by default)
CUPS_CSPACE_RGBA | Red, green, blue, alpha (DeviceRGB, sRGB by default)
CUPS_CSPACE_RGBW | Red, green, blue, white (DeviceRGB, sRGB by default)
CUPS_CSPACE_SILVER DEPRECATED | Silver foil
CUPS_CSPACE_SRGB | Red, green, blue (sRGB)
CUPS_CSPACE_SW | Luminance (gamma 2.2)
CUPS_CSPACE_W | Luminance (DeviceGray, gamma 2.2 by default)
CUPS_CSPACE_WHITE DEPRECATED | White ink (as black)
CUPS_CSPACE_YMC DEPRECATED | Yellow, magenta, cyan
CUPS_CSPACE_YMCK DEPRECATED | Yellow, magenta, cyan, black

### cups_cut_e

CutMedia attribute values

#### Constants

CUPS_CUT_FILE | Cut the roll after this file
CUPS_CUT_JOB | Cut the roll after this job
CUPS_CUT_NONE | Never cut the roll
CUPS_CUT_PAGE | Cut the roll after this page
CUPS_CUT_SET | Cut the roll after this set

### cups_dest_flags_e

Flags for `cupsConnectDest` and `cupsEnumDests`

#### Constants

CUPS_DEST_FLAGS_CANCELED | Operation was canceled
CUPS_DEST_FLAGS_CONNECTING | A connection is being established
CUPS_DEST_FLAGS_DEVICE | For `cupsConnectDest`: Connect to device
CUPS_DEST_FLAGS_ERROR | An error occurred
CUPS_DEST_FLAGS_MORE | There are more destinations
CUPS_DEST_FLAGS_NONE | No flags are set
CUPS_DEST_FLAGS_REMOVED | The destination has gone away
CUPS_DEST_FLAGS_RESOLVING | The destination address is being resolved
CUPS_DEST_FLAGS_UNCONNECTED | There is no connection

### cups_dnssd_flags_e

DNS-SD callback flag values

#### Constants

CUPS_DNSSD_FLAGS_ADD | Added (removed if not set)
CUPS_DNSSD_FLAGS_COLLISION | Collision occurred
CUPS_DNSSD_FLAGS_ERROR | Error occurred
CUPS_DNSSD_FLAGS_HOST_CHANGE | Host name changed
CUPS_DNSSD_FLAGS_MORE | More coming
CUPS_DNSSD_FLAGS_NETWORK_CHANGE | Network connection changed
CUPS_DNSSD_FLAGS_NONE | No flags

### cups_dnssd_rrtype_e

DNS record type values

#### Constants

CUPS_DNSSD_RRTYPE_A | Host address
CUPS_DNSSD_RRTYPE_AAAA | IPv6 Address.
CUPS_DNSSD_RRTYPE_ANY | Wildcard match
CUPS_DNSSD_RRTYPE_CERT | Certification record
CUPS_DNSSD_RRTYPE_CNAME | Canonical name
CUPS_DNSSD_RRTYPE_DHCID | DHCP Client Identifier
CUPS_DNSSD_RRTYPE_DNSKEY | DNSKEY
CUPS_DNSSD_RRTYPE_HTTPS | HTTPS Service Binding
CUPS_DNSSD_RRTYPE_KEY | Security key
CUPS_DNSSD_RRTYPE_KX | Key Exchange
CUPS_DNSSD_RRTYPE_LOC | Location Information.
CUPS_DNSSD_RRTYPE_NS | Name server
CUPS_DNSSD_RRTYPE_PTR | Domain name pointer
CUPS_DNSSD_RRTYPE_RRSIG | RRSIG
CUPS_DNSSD_RRTYPE_RT | Router
CUPS_DNSSD_RRTYPE_SIG | Security signature
CUPS_DNSSD_RRTYPE_SPF | Sender Policy Framework for E-Mail
CUPS_DNSSD_RRTYPE_TXT | One or more text strings
CUPS_DNSSD_RRTYPE_WKS | Well known service

### cups_edge_e

LeadingEdge attribute values

#### Constants

CUPS_EDGE_BOTTOM | Leading edge is the bottom of the page
CUPS_EDGE_LEFT | Leading edge is the left of the page
CUPS_EDGE_RIGHT | Leading edge is the right of the page
CUPS_EDGE_TOP | Leading edge is the top of the page

### cups_encoding_e

Language Encodings

#### Constants

CUPS_ENCODING_BG18030 | Chinese GB 18030
CUPS_ENCODING_EUC_CN | EUC Simplified Chinese
CUPS_ENCODING_EUC_JP | EUC Japanese
CUPS_ENCODING_EUC_KR | EUC Korean
CUPS_ENCODING_EUC_TW | EUC Traditional Chinese
CUPS_ENCODING_ISO8859_1 | ISO-8859-1
CUPS_ENCODING_ISO8859_10 | ISO-8859-10
CUPS_ENCODING_ISO8859_11 | ISO-8859-11
CUPS_ENCODING_ISO8859_13 | ISO-8859-13
CUPS_ENCODING_ISO8859_14 | ISO-8859-14
CUPS_ENCODING_ISO8859_15 | ISO-8859-15
CUPS_ENCODING_ISO8859_16 | ISO-8859-16
CUPS_ENCODING_ISO8859_2 | ISO-8859-2
CUPS_ENCODING_ISO8859_3 | ISO-8859-3
CUPS_ENCODING_ISO8859_4 | ISO-8859-4
CUPS_ENCODING_ISO8859_5 | ISO-8859-5
CUPS_ENCODING_ISO8859_6 | ISO-8859-6
CUPS_ENCODING_ISO8859_7 | ISO-8859-7
CUPS_ENCODING_ISO8859_8 | ISO-8859-8
CUPS_ENCODING_ISO8859_9 | ISO-8859-9
CUPS_ENCODING_JIS_X0213 | JIS X0213 aka Shift JIS
CUPS_ENCODING_KOI8_R | KOI-8-R
CUPS_ENCODING_KOI8_U | KOI-8-U
CUPS_ENCODING_MAC_ROMAN | MacRoman
CUPS_ENCODING_US_ASCII | US ASCII
CUPS_ENCODING_UTF_8 | UTF-8
CUPS_ENCODING_WINDOWS_1250 | CP-1250
CUPS_ENCODING_WINDOWS_1251 | CP-1251
CUPS_ENCODING_WINDOWS_1252 | CP-1252
CUPS_ENCODING_WINDOWS_1253 | CP-1253
CUPS_ENCODING_WINDOWS_1254 | CP-1254
CUPS_ENCODING_WINDOWS_1255 | CP-1255
CUPS_ENCODING_WINDOWS_1256 | CP-1256
CUPS_ENCODING_WINDOWS_1257 | CP-1257
CUPS_ENCODING_WINDOWS_1258 | CP-1258
CUPS_ENCODING_WINDOWS_1361 | Korean Johab
CUPS_ENCODING_WINDOWS_874 | CP-874
CUPS_ENCODING_WINDOWS_932 | Japanese JIS X0208-1990
CUPS_ENCODING_WINDOWS_936 | Simplified Chinese GB 2312-80
CUPS_ENCODING_WINDOWS_949 | Korean KS C5601-1992
CUPS_ENCODING_WINDOWS_950 | Traditional Chinese Big Five

### cups_jog_e

Jog attribute values

#### Constants

CUPS_JOG_FILE | Move pages after this file
CUPS_JOG_JOB | Move pages after this job
CUPS_JOG_NONE | Never move pages
CUPS_JOG_SET | Move pages after this set

### cups_jtype_e

JSON node type

#### Constants

CUPS_JTYPE_ARRAY | Array value
CUPS_JTYPE_FALSE | Boolean false value
CUPS_JTYPE_KEY | Object key (string)
CUPS_JTYPE_NULL | Null value
CUPS_JTYPE_NUMBER | Number value
CUPS_JTYPE_OBJECT | Object value
CUPS_JTYPE_STRING | String value
CUPS_JTYPE_TRUE | Boolean true value

### cups_jwa_e

JSON Web Algorithms

#### Constants

CUPS_JWA_ES256 | ECDSA using P-256 and SHA-256
CUPS_JWA_ES384 | ECDSA using P-384 and SHA-384
CUPS_JWA_ES512 | ECDSA using P-521 and SHA-512
CUPS_JWA_HS256 | HMAC using SHA-256
CUPS_JWA_HS384 | HMAC using SHA-384
CUPS_JWA_HS512 | HMAC using SHA-512
CUPS_JWA_NONE | No algorithm
CUPS_JWA_RS256 | RSASSA-PKCS1-v1_5 using SHA-256
CUPS_JWA_RS384 | RSASSA-PKCS1-v1_5 using SHA-384
CUPS_JWA_RS512 | RSASSA-PKCS1-v1_5 using SHA-512

### cups_jws_format_e

JSON Web Signature Formats

#### Constants

CUPS_JWS_FORMAT_COMPACT | JWS Compact Serialization
CUPS_JWS_FORMAT_JSON | JWS JSON Serialization

### cups_media_flags_e

Flags for `cupsGetDestMediaByName` and `cupsGetDestMediaBySize`

#### Constants

CUPS_MEDIA_FLAGS_BORDERLESS | Find a borderless size
CUPS_MEDIA_FLAGS_DEFAULT | Find the closest size supported by the printer
CUPS_MEDIA_FLAGS_DUPLEX | Find a size compatible with 2-sided printing
CUPS_MEDIA_FLAGS_EXACT | Find an exact match for the size
CUPS_MEDIA_FLAGS_READY | If the printer supports media sensing, find the size amongst the "ready" media.

### cups_mediapos_e

MediaPosition values

#### Constants

CUPS_MEDIAPOS_ALTERNATE | 'alternate'
CUPS_MEDIAPOS_ALTERNATE_ROLL | 'alternate-roll'
CUPS_MEDIAPOS_AUTO | 'auto'
CUPS_MEDIAPOS_BOTTOM | 'bottom'
CUPS_MEDIAPOS_BY_PASS_TRAY | 'by-pass-tray'
CUPS_MEDIAPOS_CENTER | 'center'
CUPS_MEDIAPOS_DISC | 'disc'
CUPS_MEDIAPOS_ENVELOPE | 'envelope'
CUPS_MEDIAPOS_HAGAKI | 'hagaki'
CUPS_MEDIAPOS_LARGE_CAPACITY | 'large-capacity'
CUPS_MEDIAPOS_LEFT | 'left'
CUPS_MEDIAPOS_MAIN | 'main'
CUPS_MEDIAPOS_MAIN_ROLL | 'main-roll'
CUPS_MEDIAPOS_MANUAL | 'manual'
CUPS_MEDIAPOS_MIDDLE | 'middle'
CUPS_MEDIAPOS_PHOTO | 'photo'
CUPS_MEDIAPOS_REAR | 'rear'
CUPS_MEDIAPOS_RIGHT | 'right'
CUPS_MEDIAPOS_ROLL_1 | 'roll-1'
CUPS_MEDIAPOS_ROLL_10 | 'roll-10'
CUPS_MEDIAPOS_ROLL_2 | 'roll-2'
CUPS_MEDIAPOS_ROLL_3 | 'roll-3'
CUPS_MEDIAPOS_ROLL_4 | 'roll-4'
CUPS_MEDIAPOS_ROLL_5 | 'roll-5'
CUPS_MEDIAPOS_ROLL_6 | 'roll-6'
CUPS_MEDIAPOS_ROLL_7 | 'roll-7'
CUPS_MEDIAPOS_ROLL_8 | 'roll-8'
CUPS_MEDIAPOS_ROLL_9 | 'roll-9'
CUPS_MEDIAPOS_SIDE | 'side'
CUPS_MEDIAPOS_TOP | 'top'
CUPS_MEDIAPOS_TRAY_1 | 'tray-1'
CUPS_MEDIAPOS_TRAY_10 | 'tray-10'
CUPS_MEDIAPOS_TRAY_11 | 'tray-11'
CUPS_MEDIAPOS_TRAY_12 | 'tray-12'
CUPS_MEDIAPOS_TRAY_13 | 'tray-13'
CUPS_MEDIAPOS_TRAY_14 | 'tray-14'
CUPS_MEDIAPOS_TRAY_15 | 'tray-15'
CUPS_MEDIAPOS_TRAY_16 | 'tray-16'
CUPS_MEDIAPOS_TRAY_17 | 'tray-17'
CUPS_MEDIAPOS_TRAY_18 | 'tray-18'
CUPS_MEDIAPOS_TRAY_19 | 'tray-19'
CUPS_MEDIAPOS_TRAY_2 | 'tray-2'
CUPS_MEDIAPOS_TRAY_20 | 'tray-20'
CUPS_MEDIAPOS_TRAY_3 | 'tray-3'
CUPS_MEDIAPOS_TRAY_4 | 'tray-4'
CUPS_MEDIAPOS_TRAY_5 | 'tray-5'
CUPS_MEDIAPOS_TRAY_6 | 'tray-6'
CUPS_MEDIAPOS_TRAY_7 | 'tray-7'
CUPS_MEDIAPOS_TRAY_8 | 'tray-8'
CUPS_MEDIAPOS_TRAY_9 | 'tray-9'

### cups_ogrant_e

OAuth Grant Types

#### Constants

CUPS_OGRANT_AUTHORIZATION_CODE | Authorization code
CUPS_OGRANT_DEVICE_CODE | Device code
CUPS_OGRANT_REFRESH_TOKEN | Refresh token

### cups_order_e

cupsColorOrder attribute values

#### Constants

CUPS_ORDER_BANDED | CCC MMM YYY KKK ...
CUPS_ORDER_CHUNKED | CMYK CMYK CMYK ...
CUPS_ORDER_PLANAR | CCC ... MMM ... YYY ... KKK ...

### cups_orient_e

Orientation attribute values

#### Constants

CUPS_ORIENT_0 | Don't rotate the page
CUPS_ORIENT_180 | Turn the page upside down
CUPS_ORIENT_270 | Rotate the page clockwise
CUPS_ORIENT_90 | Rotate the page counter-clockwise

### cups_ptype_e

Printer type/capability flags

#### Constants

CUPS_PTYPE_AUTHENTICATED | Printer requires authentication
CUPS_PTYPE_BIND | Can bind output
CUPS_PTYPE_BW | Can do B&W printing
CUPS_PTYPE_CLASS | Printer class
CUPS_PTYPE_COLLATE | Can quickly collate copies
CUPS_PTYPE_COLOR | Can do color printing
CUPS_PTYPE_COMMANDS | Printer supports maintenance commands
CUPS_PTYPE_COPIES | Can do copies in hardware
CUPS_PTYPE_COVER | Can cover output
CUPS_PTYPE_DEFAULT | Default printer on network
CUPS_PTYPE_DISCOVERED | Printer was discovered
CUPS_PTYPE_DUPLEX | Can do two-sided printing
CUPS_PTYPE_FAX | Fax queue
CUPS_PTYPE_FOLD | Can fold output
CUPS_PTYPE_LARGE | Can print on D/E/A1/A0-size media
CUPS_PTYPE_LOCAL | Local printer or class
CUPS_PTYPE_MEDIUM | Can print on Tabloid/B/C/A3/A2-size media
CUPS_PTYPE_MFP | Printer with scanning capabilities
CUPS_PTYPE_NOT_SHARED | Printer is not shared
CUPS_PTYPE_PUNCH | Can punch output
CUPS_PTYPE_REJECTING | Printer is rejecting jobs
CUPS_PTYPE_REMOTE | Remote printer or class
CUPS_PTYPE_SCANNER | Scanner-only device
CUPS_PTYPE_SMALL | Can print on Letter/Legal/A4-size media
CUPS_PTYPE_SORT | Can sort output
CUPS_PTYPE_STAPLE | Can staple output
CUPS_PTYPE_VARIABLE | Can print on rolls and custom-size media

### cups_raster_mode_e

cupsRasterOpen modes

#### Constants

CUPS_RASTER_READ | Open stream for reading
CUPS_RASTER_WRITE | Open stream for writing
CUPS_RASTER_WRITE_COMPRESSED | Open stream for compressed writing
CUPS_RASTER_WRITE_PWG | Open stream for compressed writing in PWG Raster mode

### cups_whichjobs_e

Which jobs for `cupsGetJobs`

#### Constants

CUPS_WHICHJOBS_ACTIVE | Pending/held/processing jobs
CUPS_WHICHJOBS_ALL | All jobs
CUPS_WHICHJOBS_COMPLETED | Completed/canceled/aborted jobs

### http_encoding_e

HTTP transfer encoding values

#### Constants

HTTP_ENCODING_CHUNKED | Data is chunked
HTTP_ENCODING_FIELDS | Sending HTTP fields
HTTP_ENCODING_LENGTH | Data is sent with Content-Length

### http_encryption_e

HTTP encryption values

#### Constants

HTTP_ENCRYPTION_ALWAYS | Always encrypt (HTTPS)
HTTP_ENCRYPTION_IF_REQUESTED | Encrypt if requested (TLS upgrade)
HTTP_ENCRYPTION_NEVER | Never encrypt
HTTP_ENCRYPTION_REQUIRED | Encryption is required (TLS upgrade)

### http_field_e

HTTP field names

#### Constants

HTTP_FIELD_ACCEPT | Accept field
HTTP_FIELD_ACCEPT_CH | RFC 8942 Accept-CH field
HTTP_FIELD_ACCEPT_ENCODING | Accept-Encoding field
HTTP_FIELD_ACCEPT_LANGUAGE | Accept-Language field
HTTP_FIELD_ACCEPT_RANGES | Accept-Ranges field
HTTP_FIELD_ACCESS_CONTROL_ALLOW_CREDENTIALS | CORS/Fetch Access-Control-Allow-Cresdentials field
HTTP_FIELD_ACCESS_CONTROL_ALLOW_HEADERS | CORS/Fetch Access-Control-Allow-Headers field
HTTP_FIELD_ACCESS_CONTROL_ALLOW_METHODS | CORS/Fetch Access-Control-Allow-Methods field
HTTP_FIELD_ACCESS_CONTROL_ALLOW_ORIGIN | CORS/Fetch Access-Control-Allow-Origin field
HTTP_FIELD_ACCESS_CONTROL_EXPOSE_HEADERS | CORS/Fetch Access-Control-Expose-Headers field
HTTP_FIELD_ACCESS_CONTROL_MAX_AGE | CORS/Fetch Access-Control-Max-Age field
HTTP_FIELD_ACCESS_CONTROL_REQUEST_HEADERS | CORS/Fetch Access-Control-Request-Headers field
HTTP_FIELD_ACCESS_CONTROL_REQUEST_METHOD | CORS/Fetch Access-Control-Request-Method field
HTTP_FIELD_AGE | Age field
HTTP_FIELD_ALLOW | Allow field
HTTP_FIELD_AUTHENTICATION_CONTROL | RFC 8053 Authentication-Control field
HTTP_FIELD_AUTHENTICATION_INFO | Authentication-Info field
HTTP_FIELD_AUTHORIZATION | Authorization field
HTTP_FIELD_CACHE_CONTROL | Cache-Control field
HTTP_FIELD_CACHE_STATUS | Cache-Status field
HTTP_FIELD_CERT_NOT_AFTER | RFC 8739 (ACME) Cert-Not-After field
HTTP_FIELD_CERT_NOT_BEFORE | RFC 8739 (ACME) Cert-Not-Before field
HTTP_FIELD_CONNECTION | Connection field
HTTP_FIELD_CONTENT_DISPOSITION | RFC 6266 Content-Disposition field
HTTP_FIELD_CONTENT_ENCODING | Content-Encoding field
HTTP_FIELD_CONTENT_LANGUAGE | Content-Language field
HTTP_FIELD_CONTENT_LENGTH | Content-Length field
HTTP_FIELD_CONTENT_LOCATION | Content-Location field
HTTP_FIELD_CONTENT_RANGE | Content-Range field
HTTP_FIELD_CONTENT_SECURITY_POLICY | CSPL3 Content-Security-Policy field
HTTP_FIELD_CONTENT_SECURITY_POLICY_REPORT_ONLY | CSPL3 Content-Security-Policy-Report-Only field
HTTP_FIELD_CONTENT_TYPE | Content-Type field
HTTP_FIELD_CROSS_ORIGIN_EMBEDDER_POLICY | WHATWG Cross-Origin-Embedder-Policy field
HTTP_FIELD_CROSS_ORIGIN_EMBEDDER_POLICY_REPORT_ONLY | WHATWG Cross-Origin-Embedder-Policy-Report-Only field
HTTP_FIELD_CROSS_ORIGIN_OPENER_POLICY | WHATWG Cross-Origin-Opener-Policy field
HTTP_FIELD_CROSS_ORIGIN_OPENER_POLICY_REPORT_ONLY | WHATWG Cross-Origin-Opener-Policy-Report-Only field
HTTP_FIELD_CROSS_ORIGIN_RESOURCE_POLICY | WHATWG Cross-Origin-Resource-Policy field
HTTP_FIELD_DASL | RFC 5323 (WebDAV) DASL field
HTTP_FIELD_DATE | Date field
HTTP_FIELD_DAV | RFC 4918 (WebDAV) DAV field
HTTP_FIELD_DEPTH | RFC 4918 (WebDAV) Depth field
HTTP_FIELD_DESTINATION | RFC 4918 (WebDAV) Destination field
HTTP_FIELD_ETAG | ETag field
HTTP_FIELD_EXPIRES | Expires field
HTTP_FIELD_FORWARDED | RFC 7239 Forwarded field
HTTP_FIELD_FROM | From field
HTTP_FIELD_HOST | Host field
HTTP_FIELD_IF | RFC 4918 (WebDAV) If field
HTTP_FIELD_IF_MATCH | If-Match field
HTTP_FIELD_IF_MODIFIED_SINCE | If-Modified-Since field
HTTP_FIELD_IF_NONE_MATCH | If-None-Match field
HTTP_FIELD_IF_RANGE | If-Range field
HTTP_FIELD_IF_SCHEDULE_TAG_MATCH | RFC 6638 (CalDAV) If-Schedule-Tag-Match field
HTTP_FIELD_IF_UNMODIFIED_SINCE | If-Unmodified-Since field
HTTP_FIELD_KEEP_ALIVE | Keep-Alive field
HTTP_FIELD_LAST_MODIFIED | Last-Modified field
HTTP_FIELD_LINK | Link field
HTTP_FIELD_LOCATION | Location field
HTTP_FIELD_LOCK_TOKEN | RFC 4918 (WebDAV) Lock-Token field
HTTP_FIELD_MAX | Maximum field index
HTTP_FIELD_MAX_FORWARDS | Max-Forwards field
HTTP_FIELD_OPTIONAL_WWW_AUTHENTICATE | RFC 8053 Optional-WWW-Authenticate field
HTTP_FIELD_ORIGIN | RFC 6454 Origin field
HTTP_FIELD_OSCORE | RFC 8613 OSCORE field
HTTP_FIELD_OVERWRITE | RFC 4918 (WebDAV) Overwrite field
HTTP_FIELD_PRAGMA | Pragma field
HTTP_FIELD_PROXY_AUTHENTICATE | Proxy-Authenticate field
HTTP_FIELD_PROXY_AUTHENTICATION_INFO | Proxy-Authentication-Info field
HTTP_FIELD_PROXY_AUTHORIZATION | Proxy-Authorization field
HTTP_FIELD_PROXY_STATUS | Proxy-Status field
HTTP_FIELD_PUBLIC | Public field
HTTP_FIELD_RANGE | Range field
HTTP_FIELD_REFERER | Referer field
HTTP_FIELD_REFRESH | WHATWG Refresh field
HTTP_FIELD_REPLAY_NONCE | RFC 8555 (ACME) Replay-Nonce field
HTTP_FIELD_RETRY_AFTER | Retry-After field
HTTP_FIELD_SCHEDULE_REPLY | RFC 6638 (CalDAV) Schedule-Reply field
HTTP_FIELD_SCHEDULE_TAG | RFC 6638 (CalDAV) Schedule-Tag field
HTTP_FIELD_SERVER | Server field
HTTP_FIELD_STRICT_TRANSPORT_SECURITY | HSTS Strict-Transport-Security field
HTTP_FIELD_TE | TE field
HTTP_FIELD_TIMEOUT | RFC 4918 Timeout field
HTTP_FIELD_TRAILER | Trailer field
HTTP_FIELD_TRANSFER_ENCODING | Transfer-Encoding field
HTTP_FIELD_UNKNOWN | Unknown field
HTTP_FIELD_UPGRADE | Upgrade field
HTTP_FIELD_USER_AGENT | User-Agent field
HTTP_FIELD_VARY | Vary field
HTTP_FIELD_VIA | Via field
HTTP_FIELD_WWW_AUTHENTICATE | WWW-Authenticate field
HTTP_FIELD_X_CONTENT_OPTIONS | WHATWG X-Content-Options field
HTTP_FIELD_X_FRAME_OPTIONS | WHATWG X-Frame-Options field

### http_keepalive_e

HTTP keep-alive values

#### Constants

HTTP_KEEPALIVE_OFF | No keep alive support
HTTP_KEEPALIVE_ON | Use keep alive

### http_resolve_e

`httpResolveURI` options bit values

#### Constants

HTTP_RESOLVE_DEFAULT | Resolve with default options
HTTP_RESOLVE_FAXOUT | Resolve FaxOut service instead of Print
HTTP_RESOLVE_FQDN | Resolve to a FQDN

### http_state_e

HTTP state values; states are server-oriented...

#### Constants

HTTP_STATE_CONNECT | CONNECT command, waiting for blank line
HTTP_STATE_COPY | COPY command, waiting for blank line
HTTP_STATE_COPY_SEND | COPY command, sending data
HTTP_STATE_DELETE | DELETE command, waiting for blank line
HTTP_STATE_DELETE_SEND | DELETE command, sending data
HTTP_STATE_ERROR | Error on socket
HTTP_STATE_GET | GET command, waiting for blank line
HTTP_STATE_GET_SEND | GET command, sending data
HTTP_STATE_HEAD | HEAD command, waiting for blank line
HTTP_STATE_LOCK | LOCK command, waiting for blank line
HTTP_STATE_LOCK_RECV | LOCK command, receiving data
HTTP_STATE_LOCK_SEND | LOCK command, sending data
HTTP_STATE_MKCOL | MKCOL command, waiting for blank line
HTTP_STATE_MOVE | MOVE command, waiting for blank line
HTTP_STATE_MOVE_SEND | MOVE command, sending data
HTTP_STATE_OPTIONS | OPTIONS command, waiting for blank line
HTTP_STATE_POST | POST command, waiting for blank line
HTTP_STATE_POST_RECV | POST command, receiving data
HTTP_STATE_POST_SEND | POST command, sending data
HTTP_STATE_PROPFIND | PROPFIND command, waiting for blank line
HTTP_STATE_PROPFIND_RECV | PROPFIND command, receiving data
HTTP_STATE_PROPFIND_SEND | PROPFIND command, sending data
HTTP_STATE_PROPPATCH | PROPPATCH command, waiting for blank line
HTTP_STATE_PROPPATCH_RECV | PROPPATCH command, receiving data
HTTP_STATE_PROPPATCH_SEND | PROPPATCH command, sending data
HTTP_STATE_PUT | PUT command, waiting for blank line
HTTP_STATE_PUT_RECV | PUT command, receiving data
HTTP_STATE_STATUS | Command complete, sending status
HTTP_STATE_TRACE | TRACE command, waiting for blank line
HTTP_STATE_UNKNOWN_METHOD | Unknown request method, waiting for blank line
HTTP_STATE_UNKNOWN_VERSION | Unknown request method, waiting for blank line
HTTP_STATE_UNLOCK | UNLOCK command, waiting for blank line
HTTP_STATE_WAITING | Waiting for command

### http_status_e

HTTP status codes

#### Constants

HTTP_STATUS_ACCEPTED | DELETE command was successful
HTTP_STATUS_ALREADY_REPORTED | Already reported (WebDAV)
HTTP_STATUS_BAD_GATEWAY | Bad gateway
HTTP_STATUS_BAD_REQUEST | Bad request
HTTP_STATUS_CONFLICT | Request is self-conflicting
HTTP_STATUS_CONTENT_TOO_LARGE | Content too large
HTTP_STATUS_CONTINUE | Everything OK, keep going...
HTTP_STATUS_CREATED | PUT command was successful
HTTP_STATUS_CUPS_AUTHORIZATION_CANCELED | User canceled authorization
HTTP_STATUS_CUPS_PKI_ERROR | Error negotiating a secure connection
HTTP_STATUS_ERROR | An error response from httpXxxx()
HTTP_STATUS_EXPECTATION_FAILED | The expectation given in an Expect header field was not met
HTTP_STATUS_FAILED_DEPENDENCY | Failed dependency (WebDAV)
HTTP_STATUS_FORBIDDEN | Forbidden to access this URI
HTTP_STATUS_FOUND | Document was found at a different URI
HTTP_STATUS_GATEWAY_TIMEOUT | Gateway connection timed out
HTTP_STATUS_GONE | Server has gone away
HTTP_STATUS_HTTP_VERSION_NOT_SUPPORTED | HTTP version not supported
HTTP_STATUS_INSUFFICIENT_STORAGE | Insufficient storage (WebDAV)
HTTP_STATUS_LENGTH_REQUIRED | A content length or encoding is required
HTTP_STATUS_LOCKED | Locked (WebDAV)
HTTP_STATUS_LOOP_DETECTED | Loop detected (WebDAV)
HTTP_STATUS_METHOD_NOT_ALLOWED | Method is not allowed
HTTP_STATUS_MISDIRECTED_REQUEST | Misdirected request
HTTP_STATUS_MOVED_PERMANENTLY | Document has moved permanently
HTTP_STATUS_MULTIPLE_CHOICES | Multiple files match request
HTTP_STATUS_MULTI_STATUS | Multiple status codes (WebDAV)
HTTP_STATUS_NETWORK_AUTHENTICATION_REQUIRED | Network Authentication Required (WebDAV)
HTTP_STATUS_NONE | No Expect value
HTTP_STATUS_NOT_ACCEPTABLE | Not Acceptable
HTTP_STATUS_NOT_AUTHORITATIVE | Information isn't authoritative
HTTP_STATUS_NOT_FOUND | URI was not found
HTTP_STATUS_NOT_IMPLEMENTED | Feature not implemented
HTTP_STATUS_NOT_MODIFIED | File not modified
HTTP_STATUS_NO_CONTENT | Successful command, no new data
HTTP_STATUS_OK | OPTIONS/GET/HEAD/POST/TRACE command was successful
HTTP_STATUS_PARTIAL_CONTENT | Only a partial file was received/sent
HTTP_STATUS_PAYMENT_REQUIRED | Payment required
HTTP_STATUS_PERMANENT_REDIRECT | Permanent redirection
HTTP_STATUS_PRECONDITION_FAILED | Precondition failed
HTTP_STATUS_PRECONDITION_REQUIRED | Precondition required (WebDAV)
HTTP_STATUS_PROXY_AUTHENTICATION_REQUIRED | Proxy Authentication is Required
HTTP_STATUS_RANGE_NOT_SATISFIABLE | The requested range is not satisfiable
HTTP_STATUS_REQUEST_HEADER_FIELDS_TOO_LARGE | Request Header Fields Too Large (WebDAV)
HTTP_STATUS_REQUEST_TIMEOUT | Request timed out
HTTP_STATUS_RESET_CONTENT | Content was reset/recreated
HTTP_STATUS_SEE_OTHER | See this other link
HTTP_STATUS_SERVER_ERROR | Internal server error
HTTP_STATUS_SERVICE_UNAVAILABLE | Service is unavailable
HTTP_STATUS_SWITCHING_PROTOCOLS | HTTP upgrade to TLS/SSL
HTTP_STATUS_TEMPORARY_REDIRECT | Temporary redirection
HTTP_STATUS_TOO_EARLY | Too early (WebDAV)
HTTP_STATUS_TOO_MANY_REQUESTS | Too many requests (WebDAV)
HTTP_STATUS_UNAUTHORIZED | Unauthorized to access host
HTTP_STATUS_UNAVAILABLE_FOR_LEGAL_REASONS | Unavailable For Legal Reasons (RFC 7725)
HTTP_STATUS_UNPROCESSABLE_CONTENT | Unprocessable content
HTTP_STATUS_UNSUPPORTED_MEDIA_TYPE | The requested media type is unsupported
HTTP_STATUS_UPGRADE_REQUIRED | Upgrade to SSL/TLS required
HTTP_STATUS_URI_TOO_LONG | URI too long
HTTP_STATUS_USE_PROXY | Must use a proxy to access this URI

### http_trust_e

Level of trust for credentials

#### Constants

HTTP_TRUST_CHANGED | Credentials have changed
HTTP_TRUST_EXPIRED | Credentials are expired
HTTP_TRUST_INVALID | Credentials are invalid
HTTP_TRUST_OK | Credentials are OK/trusted
HTTP_TRUST_RENEWED | Credentials have been renewed
HTTP_TRUST_UNKNOWN | Credentials are unknown/new

### http_uri_coding_e

URI en/decode flags

#### Constants

HTTP_URI_CODING_ALL | En/decode everything
HTTP_URI_CODING_HOSTNAME | En/decode the hostname portion
HTTP_URI_CODING_MOST | En/decode all but the query
HTTP_URI_CODING_NONE | Don't en/decode anything
HTTP_URI_CODING_QUERY | En/decode the query portion
HTTP_URI_CODING_RESOURCE | En/decode the resource portion
HTTP_URI_CODING_RFC6874 | Use RFC 6874 address format
HTTP_URI_CODING_USERNAME | En/decode the username portion

### http_uri_status_e

URI separation status

#### Constants

HTTP_URI_STATUS_BAD_ARGUMENTS | Bad arguments to function (error)
HTTP_URI_STATUS_BAD_HOSTNAME | Bad hostname in URI (error)
HTTP_URI_STATUS_BAD_PORT | Bad port number in URI (error)
HTTP_URI_STATUS_BAD_RESOURCE | Bad resource in URI (error)
HTTP_URI_STATUS_BAD_SCHEME | Bad scheme in URI (error)
HTTP_URI_STATUS_BAD_URI | Bad/empty URI (error)
HTTP_URI_STATUS_BAD_USERNAME | Bad username in URI (error)
HTTP_URI_STATUS_MISSING_RESOURCE | Missing resource in URI (warning)
HTTP_URI_STATUS_MISSING_SCHEME | Missing scheme in URI (warning)
HTTP_URI_STATUS_OK | URI decoded OK
HTTP_URI_STATUS_OVERFLOW | URI buffer for httpAssembleURI is too small
HTTP_URI_STATUS_UNKNOWN_SCHEME | Unknown scheme in URI (warning)

### http_version_e

HTTP version numbers

#### Constants

HTTP_VERSION_0_9 | HTTP/0.9
HTTP_VERSION_1_0 | HTTP/1.0
HTTP_VERSION_1_1 | HTTP/1.1

### ipp_dstate_e

"document-state" values

#### Constants

IPP_DSTATE_ABORTED | Document is aborted
IPP_DSTATE_CANCELED | Document is canceled
IPP_DSTATE_COMPLETED | Document is completed
IPP_DSTATE_PENDING | Document is pending
IPP_DSTATE_PROCESSING | Document is processing

### ipp_finishings_e

"finishings" values

#### Constants

IPP_FINISHINGS_BALE | Bale (any type)
IPP_FINISHINGS_BIND | Bind
IPP_FINISHINGS_BIND_BOTTOM | Bind on bottom
IPP_FINISHINGS_BIND_LEFT | Bind on left
IPP_FINISHINGS_BIND_RIGHT | Bind on right
IPP_FINISHINGS_BIND_TOP | Bind on top
IPP_FINISHINGS_BOOKLET_MAKER | Fold to make booklet
IPP_FINISHINGS_COAT | Apply protective liquid or powder coating
IPP_FINISHINGS_COVER | Add cover
IPP_FINISHINGS_CUPS_FOLD_ACCORDION | Accordion-fold the paper vertically into four sections
IPP_FINISHINGS_CUPS_FOLD_DOUBLE_GATE | Fold the top and bottom quarters of the paper towards the midline, then fold in half vertically
IPP_FINISHINGS_CUPS_FOLD_GATE | Fold the top and bottom quarters of the paper towards the midline
IPP_FINISHINGS_CUPS_FOLD_HALF | Fold the paper in half vertically
IPP_FINISHINGS_CUPS_FOLD_HALF_Z | Fold the paper in half horizontally, then Z-fold the paper vertically
IPP_FINISHINGS_CUPS_FOLD_LEFT_GATE | Fold the top quarter of the paper towards the midline
IPP_FINISHINGS_CUPS_FOLD_LETTER | Fold the paper into three sections vertically; sometimes also known as a C fold
IPP_FINISHINGS_CUPS_FOLD_PARALLEL | Fold the paper in half vertically two times, yielding four sections
IPP_FINISHINGS_CUPS_FOLD_POSTER | Fold the paper in half horizontally and vertically; sometimes also called a cross fold
IPP_FINISHINGS_CUPS_FOLD_RIGHT_GATE | Fold the bottom quarter of the paper towards the midline
IPP_FINISHINGS_CUPS_FOLD_Z | Fold the paper vertically into three sections, forming a Z
IPP_FINISHINGS_CUPS_PUNCH_BOTTOM_LEFT | Punch 1 hole bottom left
IPP_FINISHINGS_CUPS_PUNCH_BOTTOM_RIGHT | Punch 1 hole bottom right
IPP_FINISHINGS_CUPS_PUNCH_DUAL_BOTTOM | Punch 2 holes bottom edge
IPP_FINISHINGS_CUPS_PUNCH_DUAL_LEFT | Punch 2 holes left side
IPP_FINISHINGS_CUPS_PUNCH_DUAL_RIGHT | Punch 2 holes right side
IPP_FINISHINGS_CUPS_PUNCH_DUAL_TOP | Punch 2 holes top edge
IPP_FINISHINGS_CUPS_PUNCH_QUAD_BOTTOM | Punch 4 holes bottom edge
IPP_FINISHINGS_CUPS_PUNCH_QUAD_LEFT | Punch 4 holes left side
IPP_FINISHINGS_CUPS_PUNCH_QUAD_RIGHT | Punch 4 holes right side
IPP_FINISHINGS_CUPS_PUNCH_QUAD_TOP | Punch 4 holes top edge
IPP_FINISHINGS_CUPS_PUNCH_TOP_LEFT | Punch 1 hole top left
IPP_FINISHINGS_CUPS_PUNCH_TOP_RIGHT | Punch 1 hole top right
IPP_FINISHINGS_CUPS_PUNCH_TRIPLE_BOTTOM | Punch 3 holes bottom edge
IPP_FINISHINGS_CUPS_PUNCH_TRIPLE_LEFT | Punch 3 holes left side
IPP_FINISHINGS_CUPS_PUNCH_TRIPLE_RIGHT | Punch 3 holes right side
IPP_FINISHINGS_CUPS_PUNCH_TRIPLE_TOP | Punch 3 holes top edge
IPP_FINISHINGS_EDGE_STITCH | Stitch along any side
IPP_FINISHINGS_EDGE_STITCH_BOTTOM | Stitch along bottom edge
IPP_FINISHINGS_EDGE_STITCH_LEFT | Stitch along left side
IPP_FINISHINGS_EDGE_STITCH_RIGHT | Stitch along right side
IPP_FINISHINGS_EDGE_STITCH_TOP | Stitch along top edge
IPP_FINISHINGS_FOLD | Fold (any type)
IPP_FINISHINGS_FOLD_ACCORDION | Accordion-fold the paper vertically into four sections
IPP_FINISHINGS_FOLD_DOUBLE_GATE | Fold the top and bottom quarters of the paper towards the midline, then fold in half vertically
IPP_FINISHINGS_FOLD_ENGINEERING_Z | Fold the paper vertically into two small sections and one larger, forming an elongated Z
IPP_FINISHINGS_FOLD_GATE | Fold the top and bottom quarters of the paper towards the midline
IPP_FINISHINGS_FOLD_HALF | Fold the paper in half vertically
IPP_FINISHINGS_FOLD_HALF_Z | Fold the paper in half horizontally, then Z-fold the paper vertically
IPP_FINISHINGS_FOLD_LEFT_GATE | Fold the top quarter of the paper towards the midline
IPP_FINISHINGS_FOLD_LETTER | Fold the paper into three sections vertically; sometimes also known as a C fold
IPP_FINISHINGS_FOLD_PARALLEL | Fold the paper in half vertically two times, yielding four sections
IPP_FINISHINGS_FOLD_POSTER | Fold the paper in half horizontally and vertically; sometimes also called a cross fold
IPP_FINISHINGS_FOLD_RIGHT_GATE | Fold the bottom quarter of the paper towards the midline
IPP_FINISHINGS_FOLD_Z | Fold the paper vertically into three sections, forming a Z
IPP_FINISHINGS_JOG_OFFSET | Offset for binding (any type)
IPP_FINISHINGS_LAMINATE | Apply protective (solid) material
IPP_FINISHINGS_NONE | No finishing
IPP_FINISHINGS_PUNCH | Punch (any location/count)
IPP_FINISHINGS_PUNCH_BOTTOM_LEFT | Punch 1 hole bottom left
IPP_FINISHINGS_PUNCH_BOTTOM_RIGHT | Punch 1 hole bottom right
IPP_FINISHINGS_PUNCH_DUAL_BOTTOM | Punch 2 holes bottom edge
IPP_FINISHINGS_PUNCH_DUAL_LEFT | Punch 2 holes left side
IPP_FINISHINGS_PUNCH_DUAL_RIGHT | Punch 2 holes right side
IPP_FINISHINGS_PUNCH_DUAL_TOP | Punch 2 holes top edge
IPP_FINISHINGS_PUNCH_MULTIPLE_BOTTOM | Punch multiple holes bottom edge
IPP_FINISHINGS_PUNCH_MULTIPLE_LEFT | Punch multiple holes left side
IPP_FINISHINGS_PUNCH_MULTIPLE_RIGHT | Punch multiple holes right side
IPP_FINISHINGS_PUNCH_MULTIPLE_TOP | Punch multiple holes top edge
IPP_FINISHINGS_PUNCH_QUAD_BOTTOM | Punch 4 holes bottom edge
IPP_FINISHINGS_PUNCH_QUAD_LEFT | Punch 4 holes left side
IPP_FINISHINGS_PUNCH_QUAD_RIGHT | Punch 4 holes right side
IPP_FINISHINGS_PUNCH_QUAD_TOP | Punch 4 holes top edge
IPP_FINISHINGS_PUNCH_TOP_LEFT | Punch 1 hole top left
IPP_FINISHINGS_PUNCH_TOP_RIGHT | Punch 1 hole top right
IPP_FINISHINGS_PUNCH_TRIPLE_BOTTOM | Punch 3 holes bottom edge
IPP_FINISHINGS_PUNCH_TRIPLE_LEFT | Punch 3 holes left side
IPP_FINISHINGS_PUNCH_TRIPLE_RIGHT | Punch 3 holes right side
IPP_FINISHINGS_PUNCH_TRIPLE_TOP | Punch 3 holes top edge
IPP_FINISHINGS_SADDLE_STITCH | Staple interior
IPP_FINISHINGS_STAPLE | Staple (any location/method)
IPP_FINISHINGS_STAPLE_BOTTOM_LEFT | Staple bottom left corner
IPP_FINISHINGS_STAPLE_BOTTOM_RIGHT | Staple bottom right corner
IPP_FINISHINGS_STAPLE_DUAL_BOTTOM | Two staples on bottom
IPP_FINISHINGS_STAPLE_DUAL_LEFT | Two staples on left
IPP_FINISHINGS_STAPLE_DUAL_RIGHT | Two staples on right
IPP_FINISHINGS_STAPLE_DUAL_TOP | Two staples on top
IPP_FINISHINGS_STAPLE_TOP_LEFT | Staple top left corner
IPP_FINISHINGS_STAPLE_TOP_RIGHT | Staple top right corner
IPP_FINISHINGS_STAPLE_TRIPLE_BOTTOM | Three staples on bottom
IPP_FINISHINGS_STAPLE_TRIPLE_LEFT | Three staples on left
IPP_FINISHINGS_STAPLE_TRIPLE_RIGHT | Three staples on right
IPP_FINISHINGS_STAPLE_TRIPLE_TOP | Three staples on top
IPP_FINISHINGS_TRIM | Trim (any type)
IPP_FINISHINGS_TRIM_AFTER_COPIES | Trim output after each copy
IPP_FINISHINGS_TRIM_AFTER_DOCUMENTS | Trim output after each document
IPP_FINISHINGS_TRIM_AFTER_JOB | Trim output after job
IPP_FINISHINGS_TRIM_AFTER_PAGES | Trim output after each page

### ipp_jstate_e

"job-state" values

#### Constants

IPP_JSTATE_ABORTED | Job has aborted due to error
IPP_JSTATE_CANCELED | Job has been canceled
IPP_JSTATE_COMPLETED | Job has completed successfully
IPP_JSTATE_HELD | Job is held for printing
IPP_JSTATE_PENDING | Job is waiting to be printed
IPP_JSTATE_PROCESSING | Job is currently printing
IPP_JSTATE_STOPPED | Job has been stopped

### ipp_op_e

IPP operations

#### Constants

IPP_OP_ACKNOWLEDGE_DOCUMENT | Acknowledge-Document: Acknowledge processing of a document
IPP_OP_ACKNOWLEDGE_ENCRYPTED_JOB_ATTRIBUTES | Acknowledge-Encrypted-Job-Attributes: Acknowledge receipt of encrypted job attributes
IPP_OP_ACKNOWLEDGE_IDENTIFY_PRINTER | Acknowledge-Identify-Printer: Acknowledge action on an Identify-Printer request
IPP_OP_ACKNOWLEDGE_JOB | Acknowledge-Job: Acknowledge processing of a job
IPP_OP_ACTIVATE_PRINTER DEPRECATED | Activate-Printer: Start a printer and accept jobs
IPP_OP_ADD_DOCUMENT_IMAGES | Add-Document-Images: Add image(s) from the specified scanner source
IPP_OP_ALLOCATE_PRINTER_RESOURCES | Allocate-Printer-Resources: Use resources for a printer.
IPP_OP_CANCEL_CURRENT_JOB | Cancel-Current-Job: Cancel the current job
IPP_OP_CANCEL_DOCUMENT | Cancel-Document: Cancel a document
IPP_OP_CANCEL_JOB | Cancel-Job: Cancel a job
IPP_OP_CANCEL_JOBS | Cancel-Jobs: Cancel all jobs (administrative)
IPP_OP_CANCEL_MY_JOBS | Cancel-My-Jobs: Cancel a user's jobs
IPP_OP_CANCEL_RESOURCE | Cancel-Resource: Uninstall a resource.
IPP_OP_CANCEL_SUBSCRIPTION | Cancel-Subscription: Cancel a subscription
IPP_OP_CLOSE_JOB | Close-Job: Close a job and start printing
IPP_OP_CREATE_JOB | Create-Job: Create an empty print job
IPP_OP_CREATE_JOB_SUBSCRIPTIONS | Create-Job-Subscriptions: Create one of more job subscriptions
IPP_OP_CREATE_PRINTER | Create-Printer: Create a new service.
IPP_OP_CREATE_PRINTER_SUBSCRIPTIONS | Create-Printer-Subscriptions: Create one or more printer subscriptions
IPP_OP_CREATE_RESOURCE | Create-Resource: Create a new (empty) resource.
IPP_OP_CREATE_RESOURCE_SUBSCRIPTIONS | Create-Resource-Subscriptions: Create event subscriptions for a resource.
IPP_OP_CREATE_SYSTEM_SUBSCRIPTIONS | Create-System-Subscriptions: Create event subscriptions for a system.
IPP_OP_CUPS_ACCEPT_JOBS DEPRECATED | CUPS-Accept-Jobs: Accept new jobs on a printer
IPP_OP_CUPS_ADD_MODIFY_CLASS | CUPS-Add-Modify-Class: Add or modify a class
IPP_OP_CUPS_ADD_MODIFY_PRINTER | CUPS-Add-Modify-Printer: Add or modify a printer
IPP_OP_CUPS_AUTHENTICATE_JOB | CUPS-Authenticate-Job: Authenticate a job
IPP_OP_CUPS_CREATE_LOCAL_PRINTER | CUPS-Create-Local-Printer: Create a local (temporary) printer
IPP_OP_CUPS_DELETE_CLASS | CUPS-Delete-Class: Delete a class
IPP_OP_CUPS_DELETE_PRINTER | CUPS-Delete-Printer: Delete a printer
IPP_OP_CUPS_GET_CLASSES DEPRECATED | CUPS-Get-Classes: Get a list of classes
IPP_OP_CUPS_GET_DEFAULT | CUPS-Get-Default: Get the default printer
IPP_OP_CUPS_GET_DEVICES DEPRECATED | CUPS-Get-Devices: Get a list of supported devices
IPP_OP_CUPS_GET_DOCUMENT DEPRECATED | CUPS-Get-Document: Get a document file
IPP_OP_CUPS_GET_PPD DEPRECATED | CUPS-Get-PPD: Get a PPD file
IPP_OP_CUPS_GET_PPDS DEPRECATED | CUPS-Get-PPDs: Get a list of supported drivers
IPP_OP_CUPS_GET_PRINTERS | CUPS-Get-Printers: Get a list of printers and/or classes
IPP_OP_CUPS_INVALID | Invalid operation name for `ippOpValue`
IPP_OP_CUPS_MOVE_JOB | CUPS-Move-Job: Move a job to a different printer
IPP_OP_CUPS_REJECT_JOBS DEPRECATED | CUPS-Reject-Jobs: Reject new jobs on a printer
IPP_OP_CUPS_SET_DEFAULT | CUPS-Set-Default: Set the default printer
IPP_OP_DEACTIVATE_PRINTER DEPRECATED | Deactivate-Printer: Stop a printer and do not accept jobs
IPP_OP_DEALLOCATE_PRINTER_RESOURCES | Deallocate-Printer-Resources: Stop using resources for a printer.
IPP_OP_DELETE_DOCUMENT DEPRECATED | Delete-Document: Delete a document
IPP_OP_DELETE_PRINTER | Delete-Printer: Delete an existing service.
IPP_OP_DEREGISTER_OUTPUT_DEVICE | Deregister-Output-Device: Remove an output device
IPP_OP_DISABLE_ALL_PRINTERS | Disable-All-Printers: Stop accepting new jobs on all services.
IPP_OP_DISABLE_PRINTER | Disable-Printer: Reject new jobs for a printer
IPP_OP_ENABLE_ALL_PRINTERS | Enable-All-Printers: Start accepting new jobs on all services.
IPP_OP_ENABLE_PRINTER | Enable-Printer: Accept new jobs for a printer
IPP_OP_FETCH_DOCUMENT | Fetch-Document: Fetch a document for processing
IPP_OP_FETCH_ENCRYPTED_JOB_ATTRIBUTES | Fetch-Encrypted-Job-Attributes: Download encrypted job attributes
IPP_OP_FETCH_JOB | Fetch-Job: Fetch a job for processing
IPP_OP_GET_DOCUMENTS | Get-Documents: Get a list of documents in a job
IPP_OP_GET_DOCUMENT_ATTRIBUTES | Get-Document-Attributes: Get document information
IPP_OP_GET_ENCRYPTED_JOB_ATTRIBUTES | Get-Encrypted-Job-Attributes: Query job attributes and return in an encrypted form
IPP_OP_GET_JOBS | Get-Jobs: Get a list of jobs
IPP_OP_GET_JOB_ATTRIBUTES | Get-Job-Attribute: Get information about a job
IPP_OP_GET_NEXT_DOCUMENT_DATA | Get-Next-Document-Data: Scan more document data
IPP_OP_GET_NOTIFICATIONS | Get-Notifications: Get notification events
IPP_OP_GET_OUTPUT_DEVICE_ATTRIBUTES | Get-Output-Device-Attributes: Get printer information for a specific output device
IPP_OP_GET_PRINTERS | Get-Printers: Get a list of services.
IPP_OP_GET_PRINTER_ATTRIBUTES | Get-Printer-Attributes: Get information about a printer
IPP_OP_GET_PRINTER_RESOURCES | Get-Printer-Resources: Get a list of resources for a printer
IPP_OP_GET_PRINTER_SUPPORTED_VALUES | Get-Printer-Supported-Values: Get supported values
IPP_OP_GET_PRINT_SUPPORT_FILES DEPRECATED | Get-Printer-Support-Files: Get printer support files
IPP_OP_GET_RESOURCES | Get-Resources: Get list of resources
IPP_OP_GET_RESOURCE_ATTRIBUTES | Get-Resource-Attributes: Get resource information
IPP_OP_GET_RESOURCE_DATA DEPRECATED | Get-Resource-Data: Get resource data
IPP_OP_GET_SUBSCRIPTIONS | Get-Subscriptions: Get list of subscriptions
IPP_OP_GET_SUBSCRIPTION_ATTRIBUTES | Get-Subscription-Attributes: Get subscription information
IPP_OP_GET_SYSTEM_ATTRIBUTES | Get-System-Attributes: Get system object attributes.
IPP_OP_GET_SYSTEM_SUPPORTED_VALUES | Get-System-Supported-Values: Get supported values for system object attributes.
IPP_OP_GET_USER_PRINTER_ATTRIBUTES | Get-User-Printer-Attributes: Get printer capabilities with authentication
IPP_OP_HOLD_JOB | Hold-Job: Hold a job for printing
IPP_OP_HOLD_NEW_JOBS | Hold-New-Jobs: Hold new jobs
IPP_OP_IDENTIFY_PRINTER | Identify-Printer: Make the printer beep, flash, or display a message for identification
IPP_OP_INSTALL_RESOURCE | Install-Resource: Install a resource.
IPP_OP_PAUSE_ALL_PRINTERS | Pause-All-Printers: Stop all services immediately.
IPP_OP_PAUSE_ALL_PRINTERS_AFTER_CURRENT_JOB | Pause-All-Printers-After-Current-Job: Stop all services after processing the current jobs.
IPP_OP_PAUSE_PRINTER | Pause-Printer: Stop a printer
IPP_OP_PAUSE_PRINTER_AFTER_CURRENT_JOB | Pause-Printer-After-Current-Job: Stop printer after the current job
IPP_OP_PRINT_JOB | Print-Job: Print a single file
IPP_OP_PRINT_URI DEPRECATED | Print-URI: Print a single URL
IPP_OP_PROMOTE_JOB | Promote-Job: Promote a job to print sooner
IPP_OP_PURGE_JOBS DEPRECATED | Purge-Jobs: Delete all jobs
IPP_OP_REGISTER_OUTPUT_DEVICE | Register-Output-Device: Register a remote service.
IPP_OP_RELEASE_HELD_NEW_JOBS | Release-Held-New-Jobs: Release new jobs that were previously held
IPP_OP_RELEASE_JOB | Release-Job: Release a job for printing
IPP_OP_RENEW_SUBSCRIPTION | Renew-Subscription: Renew a printer subscription
IPP_OP_REPROCESS_JOB DEPRECATED | Reprocess-Job: Reprint a job
IPP_OP_RESTART_JOB DEPRECATED | Restart-Job: Reprint a job
IPP_OP_RESTART_ONE_PRINTER | Restart-One-Printer: Restart a single printer/service
IPP_OP_RESTART_PRINTER | Restart-Printer: Restart a printer
IPP_OP_RESTART_SYSTEM | Restart-System: Restart all services.
IPP_OP_RESUBMIT_JOB | Resubmit-Job: Copy and reprint a job
IPP_OP_RESUME_ALL_PRINTERS | Resume-All-Printers: Start job processing on all services.
IPP_OP_RESUME_JOB | Resume-Job: Resume the current job
IPP_OP_RESUME_PRINTER | Resume-Printer: Start a printer
IPP_OP_SCHEDULE_JOB_AFTER | Schedule-Job-After: Schedule a job to print after another
IPP_OP_SEND_DOCUMENT | Send-Document: Add a file to a job
IPP_OP_SEND_NOTIFICATIONS | Send-Notifications: Send notification events
IPP_OP_SEND_RESOURCE_DATA | Send-Resource-Data: Upload the data for a resource.
IPP_OP_SEND_URI DEPRECATED | Send-URI: Add a URL to a job
IPP_OP_SET_DOCUMENT_ATTRIBUTES | Set-Document-Attributes: Set document values
IPP_OP_SET_JOB_ATTRIBUTES | Set-Job-Attributes: Set job values
IPP_OP_SET_PRINTER_ATTRIBUTES | Set-Printer-Attributes: Set printer values
IPP_OP_SET_RESOURCE_ATTRIBUTES | Set-Resource-Attributes: Set resource object attributes.
IPP_OP_SET_SYSTEM_ATTRIBUTES | Set-System-Attributes: Set system object attributes.
IPP_OP_SHUTDOWN_ALL_PRINTERS | Shutdown-All-Printers: Shutdown all services.
IPP_OP_SHUTDOWN_ONE_PRINTER | Shutdown-One-Printer: Shutdown a service.
IPP_OP_SHUTDOWN_PRINTER | Shutdown-Printer: Turn a printer off
IPP_OP_STARTUP_ALL_PRINTERS | Startup-All-Printers: Startup all services.
IPP_OP_STARTUP_ONE_PRINTER | Startup-One-Printer: Start a service.
IPP_OP_STARTUP_PRINTER | Startup-Printer: Turn a printer on
IPP_OP_SUSPEND_CURRENT_JOB | Suspend-Current-Job: Suspend the current job
IPP_OP_UPDATE_ACTIVE_JOBS | Update-Active-Jobs: Update the list of active jobs that a proxy has processed
IPP_OP_UPDATE_DOCUMENT_STATUS | Update-Document-Status: Update document values
IPP_OP_UPDATE_JOB_STATUS | Update-Job-Status: Update job values
IPP_OP_UPDATE_OUTPUT_DEVICE_ATTRIBUTES | Update-Output-Device-Attributes: Update output device values
IPP_OP_VALIDATE_DOCUMENT | Validate-Document: Validate document values prior to submission
IPP_OP_VALIDATE_JOB | Validate-Job: Validate job values prior to submission

### ipp_orient_e

"orientation-requested" values

#### Constants

IPP_ORIENT_LANDSCAPE | 90 degrees counter-clockwise
IPP_ORIENT_NONE | No rotation
IPP_ORIENT_PORTRAIT | No rotation
IPP_ORIENT_REVERSE_LANDSCAPE | 90 degrees clockwise
IPP_ORIENT_REVERSE_PORTRAIT | 180 degrees

### ipp_pstate_e

"printer-state" values

#### Constants

IPP_PSTATE_IDLE | Printer is idle
IPP_PSTATE_PROCESSING | Printer is working
IPP_PSTATE_STOPPED | Printer is stopped

### ipp_quality_e

"print-quality" values

#### Constants

IPP_QUALITY_DRAFT | Draft quality
IPP_QUALITY_HIGH | High quality
IPP_QUALITY_NORMAL | Normal quality

### ipp_res_e

Resolution units

#### Constants

IPP_RES_PER_CM | Pixels per centimeter
IPP_RES_PER_INCH | Pixels per inch

### ipp_rstate_e

"resource-state" values

#### Constants

IPP_RSTATE_ABORTED | Resource has been aborted and is pending deletion.
IPP_RSTATE_AVAILABLE | Resource is available for installation.
IPP_RSTATE_CANCELED | Resource has been canceled and is pending deletion.
IPP_RSTATE_INSTALLED | Resource is installed.
IPP_RSTATE_PENDING | Resource is created but has no data yet.

### ipp_sstate_e

"system-state" values

#### Constants

IPP_SSTATE_IDLE | At least one printer is idle and none are processing a job.
IPP_SSTATE_PROCESSING | At least one printer is processing a job.
IPP_SSTATE_STOPPED | All printers are stopped.

### ipp_state_e

`ipp_t` state values

#### Constants

IPP_STATE_ATTRIBUTE | One or more attributes need to be sent/received
IPP_STATE_DATA | IPP request data needs to be sent/received
IPP_STATE_ERROR | An error occurred
IPP_STATE_HEADER | The request header needs to be sent/received
IPP_STATE_IDLE | Nothing is happening/request completed

### ipp_status_e

IPP status code values

#### Constants

IPP_STATUS_CUPS_INVALID | Invalid status name for `ippErrorValue`
IPP_STATUS_ERROR_ACCOUNT_AUTHORIZATION_FAILED | client-error-account-authorization-failed
IPP_STATUS_ERROR_ACCOUNT_CLOSED | client-error-account-closed
IPP_STATUS_ERROR_ACCOUNT_INFO_NEEDED | client-error-account-info-needed
IPP_STATUS_ERROR_ACCOUNT_LIMIT_REACHED | client-error-account-limit-reached
IPP_STATUS_ERROR_ATTRIBUTES_NOT_SETTABLE | client-error-attributes-not-settable
IPP_STATUS_ERROR_ATTRIBUTES_OR_VALUES | client-error-attributes-or-values-not-supported
IPP_STATUS_ERROR_BAD_REQUEST | client-error-bad-request
IPP_STATUS_ERROR_BUSY | server-error-busy
IPP_STATUS_ERROR_CHARSET | client-error-charset-not-supported
IPP_STATUS_ERROR_COMPRESSION_ERROR | client-error-compression-error
IPP_STATUS_ERROR_COMPRESSION_NOT_SUPPORTED | client-error-compression-not-supported
IPP_STATUS_ERROR_CONFLICTING | client-error-conflicting-attributes
IPP_STATUS_ERROR_CUPS_AUTHENTICATION_CANCELED | cups-authentication-canceled - Authentication canceled by user
IPP_STATUS_ERROR_CUPS_OAUTH | cups-oauth - OAuth error
IPP_STATUS_ERROR_CUPS_PKI | cups-pki-error - Error negotiating a secure connection
IPP_STATUS_ERROR_CUPS_UPGRADE_REQUIRED | cups-upgrade-required - TLS upgrade required
IPP_STATUS_ERROR_DEVICE | server-error-device-error
IPP_STATUS_ERROR_DOCUMENT_ACCESS | client-error-document-access-error
IPP_STATUS_ERROR_DOCUMENT_FORMAT_ERROR | client-error-document-format-error
IPP_STATUS_ERROR_DOCUMENT_FORMAT_NOT_SUPPORTED | client-error-document-format-not-supported
IPP_STATUS_ERROR_DOCUMENT_PASSWORD | client-error-document-password-error
IPP_STATUS_ERROR_DOCUMENT_PERMISSION | client-error-document-permission-error
IPP_STATUS_ERROR_DOCUMENT_SECURITY | client-error-document-security-error
IPP_STATUS_ERROR_DOCUMENT_UNPRINTABLE | client-error-document-unprintable-error
IPP_STATUS_ERROR_FORBIDDEN | client-error-forbidden
IPP_STATUS_ERROR_GONE | client-error-gone
IPP_STATUS_ERROR_IGNORED_ALL_SUBSCRIPTIONS | client-error-ignored-all-subscriptions
IPP_STATUS_ERROR_INTERNAL | server-error-internal-error
IPP_STATUS_ERROR_JOB_CANCELED | server-error-job-canceled
IPP_STATUS_ERROR_MULTIPLE_JOBS_NOT_SUPPORTED | server-error-multiple-document-jobs-not-supported
IPP_STATUS_ERROR_NOT_ACCEPTING_JOBS | server-error-not-accepting-jobs
IPP_STATUS_ERROR_NOT_AUTHENTICATED | client-error-not-authenticated
IPP_STATUS_ERROR_NOT_AUTHORIZED | client-error-not-authorized
IPP_STATUS_ERROR_NOT_FETCHABLE | client-error-not-fetchable
IPP_STATUS_ERROR_NOT_FOUND | client-error-not-found
IPP_STATUS_ERROR_NOT_POSSIBLE | client-error-not-possible
IPP_STATUS_ERROR_OPERATION_NOT_SUPPORTED | server-error-operation-not-supported
IPP_STATUS_ERROR_PRINTER_IS_DEACTIVATED | server-error-printer-is-deactivated
IPP_STATUS_ERROR_REQUEST_ENTITY | client-error-request-entity-too-large
IPP_STATUS_ERROR_REQUEST_VALUE | client-error-request-value-too-long
IPP_STATUS_ERROR_SERVICE_UNAVAILABLE | server-error-service-unavailable
IPP_STATUS_ERROR_TEMPORARY | server-error-temporary-error
IPP_STATUS_ERROR_TIMEOUT | client-error-timeout
IPP_STATUS_ERROR_TOO_MANY_DOCUMENTS | server-error-too-many-documents
IPP_STATUS_ERROR_TOO_MANY_JOBS | server-error-too-many-jobs
IPP_STATUS_ERROR_TOO_MANY_SUBSCRIPTIONS | client-error-too-many-subscriptions
IPP_STATUS_ERROR_URI_SCHEME | client-error-uri-scheme-not-supported
IPP_STATUS_ERROR_VERSION_NOT_SUPPORTED | server-error-version-not-supported
IPP_STATUS_OK | successful-ok
IPP_STATUS_OK_CONFLICTING | successful-ok-conflicting-attributes
IPP_STATUS_OK_EVENTS_COMPLETE | successful-ok-events-complete
IPP_STATUS_OK_IGNORED_OR_SUBSTITUTED | successful-ok-ignored-or-substituted-attributes
IPP_STATUS_OK_IGNORED_SUBSCRIPTIONS | successful-ok-ignored-subscriptions
IPP_STATUS_OK_TOO_MANY_EVENTS | successful-ok-too-many-events

### ipp_tag_e

Value and group tag values for attributes

#### Constants

IPP_TAG_ADMINDEFINE | Admin-defined value
IPP_TAG_BEGIN_COLLECTION | Beginning of collection value
IPP_TAG_BOOLEAN | Boolean value
IPP_TAG_CHARSET | Character set value
IPP_TAG_CUPS_CONST | Bitflag for copied/const attribute values
IPP_TAG_CUPS_INVALID | Invalid tag name for `ippTagValue`
IPP_TAG_CUPS_MASK | Mask for copied attribute values
IPP_TAG_DATE | Date/time value
IPP_TAG_DEFAULT | Default value
IPP_TAG_DELETEATTR | Delete-attribute value
IPP_TAG_DOCUMENT | Document group
IPP_TAG_END | End-of-attributes
IPP_TAG_END_COLLECTION | End of collection value
IPP_TAG_ENUM | Enumeration value
IPP_TAG_EVENT_NOTIFICATION | Event group
IPP_TAG_EXTENSION | Extension point for 32-bit tags (part of value)
IPP_TAG_INTEGER | Integer value
IPP_TAG_JOB | Job group
IPP_TAG_KEYWORD | Keyword value
IPP_TAG_LANGUAGE | Language value
IPP_TAG_MEMBERNAME | Collection member name value
IPP_TAG_MIMETYPE | MIME media type value
IPP_TAG_NAME | Name value
IPP_TAG_NAMELANG | Name-with-language value
IPP_TAG_NOTSETTABLE | Not-settable value
IPP_TAG_NOVALUE | No-value value
IPP_TAG_OPERATION | Operation group
IPP_TAG_PRINTER | Printer group
IPP_TAG_RANGE | Range value
IPP_TAG_RESOLUTION | Resolution value
IPP_TAG_RESOURCE | Resource group
IPP_TAG_STRING | Octet string value
IPP_TAG_SUBSCRIPTION | Subscription group
IPP_TAG_SYSTEM | System group
IPP_TAG_TEXT | Text value
IPP_TAG_TEXTLANG | Text-with-language value
IPP_TAG_UNKNOWN | Unknown value
IPP_TAG_UNSUPPORTED_GROUP | Unsupported attributes group
IPP_TAG_UNSUPPORTED_VALUE | Unsupported value
IPP_TAG_URI | URI value
IPP_TAG_URISCHEME | URI scheme value
IPP_TAG_ZERO | Zero tag - used for separators