CUPS implements IPP/2.1 and the operations and attributes defined in the following specifications:
CUPS also provides 17 new operations and many new attributes to support multiple IPP printers and printer classes on a single host.
CUPS supports the "http", "https", "ipp", and "ipps" schemes. The following resource names are used:
So a typical printer URI would be "ipp://foo.example.com/printers/LaserJet". In addition, the CUPS scheduler also supports (when enabled) normal browser access via "http://foo.example.com:port/" and "https://foo.example.com:port/".
CUPS provides 17 vendor extension operations in addition to most of the standard IPP and registered extension operations:
| Operation Name | CUPS | Code | Brief Description |
|---|---|---|---|
| Print-Job | 1.0 | 0x0002 | Print a file. |
| Validate-Job | 1.0 | 0x0004 | Validate job attributes. |
| Create-Job | 1.1 | 0x0005 | Create a print job. |
| Send-Document | 1.1 | 0x0006 | Send a file for a print job. |
| Cancel-Job | 1.0 | 0x0008 | Cancel a print job. |
| Get-Job-Attributes | 1.0 | 0x0009 | Get job attributes. |
| Get-Jobs | 1.0 | 0x000A | Get all jobs. |
| Get-Printer-Attributes | 1.0 | 0x000B | Get printer attributes. |
| Hold-Job | 1.1 | 0x000C | Hold a job for printing. |
| Release-Job | 1.1 | 0x000D | Release a job for printing. |
| Restart-Job | 1.1 | 0x000E | Restarts a print job. |
| Pause-Printer | 1.0 | 0x0010 | Pause printing on a printer. |
| Resume-Printer | 1.0 | 0x0011 | Resume printing on a printer. |
| Purge-Jobs | 1.0 | 0x0012 | Purge all jobs. |
| Set-Printer-Attributes | 1.4 | 0x0013 | Set attributes for a printer. |
| Set-Job-Attributes | 1.1 | 0x0014 | Set attributes for a pending or held job. |
| Create-Printer-Subscription | 1.2 | 0x0016 | Creates a subscription associated with a printer or the server. |
| Create-Job-Subscription | 1.2 | 0x0017 | Creates a subscription associated with a job. |
| Get-Subscription-Attributes | 1.2 | 0x0018 | Gets the attributes for a subscription. |
| Get-Subscriptions | 1.2 | 0x0019 | Gets the attributes for zero or more subscriptions. |
| Renew-Subscription | 1.2 | 0x001A | Renews a subscription. |
| Cancel-Subscription | 1.2 | 0x001B | Cancels a subscription. |
| Get-Notifications | 1.2 | 0x001C | Get notification events for ippget subscriptions. |
| Enable-Printer | 1.2 | 0x0022 | Accepts jobs on a printer. |
| Disable-Printer | 1.2 | 0x0023 | Rejects jobs on a printer. |
| Hold-New-Jobs | 1.4 | 0x0025 | Hold new jobs by default. |
| Release-Held-New-Jobs | 1.4 | 0x0026 | Releases all jobs that were previously held. |
| Cancel-Jobs | 1.5 | 0x0038 | Cancel all jobs (administrator). |
| Cancel-My-Jobs | 1.5 | 0x0039 | Cancel all jobs (user). |
| Close-Job | 1.5 | 0x003b | Close a created job. |
| CUPS-Get-Default | 1.0 | 0x4001 | Get the default destination. |
| CUPS-Get-Printers | 1.0 | 0x4002 | Get all of the available printers. |
| CUPS-Add-Modify-Printer | 1.0 | 0x4003 | Add or modify a printer. |
| CUPS-Delete-Printer | 1.0 | 0x4004 | Delete a printer. |
| CUPS-Get-Classes | 1.0 | 0x4005 | Get all of the available printer classes. |
| CUPS-Add-Modify-Class | 1.0 | 0x4006 | Add or modify a printer class. |
| CUPS-Delete-Class | 1.0 | 0x4007 | Delete a printer class. |
| CUPS-Accept-Jobs | 1.0 | 0x4008 | Accept jobs on a printer or printer class. This operation is deprecated - use the Enable-Printer operation instead. |
| CUPS-Reject-Jobs | 1.0 | 0x4009 | Reject jobs on a printer or printer class. This operation is deprecated - use the Disable-Printer operation instead. |
| CUPS-Set-Default | 1.0 | 0x400A | Set the default destination. |
| CUPS-Get-Devices | 1.1 | 0x400B | Get all of the available devices. |
| CUPS-Get-PPDs | 1.1 | 0x400C | Get all of the available PPDs. |
| CUPS-Move-Job | 1.1 | 0x400D | Move a job to a different printer. |
| CUPS-Authenticate-Job | 1.2 | 0x400E | Authenticate a job for printing. |
| CUPS-Get-PPD | 1.3 | 0x400F | Get a PPD file. |
| CUPS-Get-Document | 1.4 | 0x4027 | Get a document file from a job. |
| CUPS-Create-Local-Printer | 2.2 | 0x4028 | Creates a local (temporary) print queue pointing to a remote IPP Everywhere printer. |
The following sections describe the operations supported by CUPS. In the interest of brevity, operations which use only the standard IPP attributes are not described.
The Cancel-Job operation (0x0008) cancels the specified job. CUPS 1.4 added support for the purge-job (boolean) operation attribute that (if 'true') removes all history and document files for the job as well.
The Purge-Jobs operation (0x0012) cancels all of the jobs on a given destination and optionally removes all history and document files for the jobs as well. CUPS 1.2 added support for the purge-job (boolean) operation attribute that (if 'false') retains all history and document files for the canceled jobs.
Note:The Cancel-Jobs and Cancel-My-Jobs operations should be used instead of Purge-Jobs.
The Create-Printer-Subscription operation (0x0016) creates a subscription for printer or server event notifications. CUPS provides several additional events in addition to the standard events in the IPP notifications specification. CUPS adds the following notify-events (1setOf type2 keyword) values:
The CUPS-Get-Default operation (0x4001) returns the default printer URI and attributes.
The following groups of attributes are supplied as part of the CUPS-Get-Default request:
Group 1: Operation Attributes
The following groups of attributes are send as part of the CUPS-Get-Default Response:
Group 1: Operation Attributes
Group 2: Printer Object Attributes
The CUPS-Get-Printers operation (0x4002) returns the printer attributes for every printer known to the system. This may include printers that are not served directly by the server.
The following groups of attributes are supplied as part of the CUPS-Get-Printers request:
Group 1: Operation Attributes
The following groups of attributes are send as part of the CUPS-Get-Printers Response:
Group 1: Operation Attributes
Group 2: Printer Object Attributes
The CUPS-Add-Modify-Printer operation (0x4003) adds a new printer or modifies an existing printer on the system.
The following groups of attributes are supplied as part of the CUPS-Add-Modify-Printer request:
Group 1: Operation Attributes
Group 2: Printer Object Attributes
The CUPS-Add-Modify-Printer request can optionally be followed by a PPD file to be used for the printer. The "ppd-name" attribute overrides any file that is attached to the end of the request with a local CUPS PPD file.
The following groups of attributes are send as part of the CUPS-Add-Modify-Printer Response:
Group 1: Operation Attributes
The CUPS-Delete-Printer operation (0x4004) removes an existing printer from the system.
The following groups of attributes are supplied as part of the CUPS-Delete-Printer request:
Group 1: Operation Attributes
The following groups of attributes are send as part of the CUPS-Delete-Printer Response:
Group 1: Operation Attributes
The CUPS-Get-Classes operation (0x4005) returns the printer attributes for every printer class known to the system. This may include printer classes that are not served directly by the server.
The following groups of attributes are supplied as part of the CUPS-Get-Classes request:
Group 1: Operation Attributes
The following groups of attributes are send as part of the CUPS-Get-Classes Response:
Group 1: Operation Attributes
Group 2: Printer Class Object Attributes
The CUPS-Add-Modify-Class operation (0x4006) adds a new printer class or modifies and existing printer class on the system.
The following groups of attributes are supplied as part of the CUPS-Add-Modify-Class request:
Group 1: Operation Attributes
Group 2: Printer Object Attributes
The following groups of attributes are send as part of the CUPS-Add-Modify-Class Response:
Group 1: Operation Attributes
The CUPS-Delete-Class operation (0x4007) removes an existing printer class from the system.
The following groups of attributes are supplied as part of the CUPS-Delete-Class request:
Group 1: Operation Attributes
The following groups of attributes are send as part of the CUPS-Delete-Class Response:
Group 1: Operation Attributes
The CUPS-Set-Default operation (0x400A) sets the default printer destination for all clients when a resource name of "/printers" is specified.
The following groups of attributes are supplied as part of the CUPS-Set-Default request:
Group 1: Operation Attributes
The following groups of attributes are send as part of the CUPS-Set-Default Response:
Group 1: Operation Attributes
The CUPS-Get-Devices operation (0x400B) returns all of the supported device-uri's for the server.
The following groups of attributes are supplied as part of the CUPS-Get-Devices request:
Group 1: Operation Attributes
The following groups of attributes are send as part of the CUPS-Get-Devices Response:
Group 1: Operation Attributes
Groups 2-N: Device Object Attributes (using printer-attributes-tag group)
The CUPS-Get-PPDs operation (0x400C) returns all of the locally available PPD files on the system.
The following groups of attributes are supplied as part of the CUPS-Get-PPDs request:
Group 1: Operation Attributes
The following groups of attributes are send as part of the CUPS-Get-PPDs Response:
Group 1: Operation Attributes
Groups 2-N: PPD Attributes (using printer-attributes-tag group)
The CUPS-Move-Job operation (0x400D) moves an active print job or all print jobs for a printer to a different printer.
The following groups of attributes are supplied as part of the CUPS-Move-Job request:
Group 1: Operation Attributes
Group 2: Job Template Attributes
The following groups of attributes are send as part of the CUPS-Move-Job Response:
Group 1: Operation Attributes
The CUPS-Authenticate-Job operation (0x400E) authenticates a print job for printing, releasing the job if it is held. Typically this is used when printing to a remote server. The authentication information is passed in the HTTP request; the HTTP connection is normally encrypted for this type of request.
The following groups of attributes are supplied as part of the CUPS-Authenticate-Job request:
Group 1: Operation Attributes
Group 2: Job Attributes
The following groups of attributes are send as part of the CUPS-Authenticate-Job Response:
Group 1: Operation Attributes
Group 2: Unsupported Attributes (status=client-eror-attributes-or-values-not-supported)
The CUPS-Get-PPD operation (0x400F) gets a PPD file from the server. The PPD file can be specified using a ppd-name returned by CUPS-Get-PPDs or using the printer-uri for a queue.
If the PPD file is found, successful-ok is returned with the PPD file following the response data.
If the PPD file cannot be served by the local server because the printer-uri attribute points to an external printer, a cups-see-other status is returned with the correct URI to use.
If the PPD file does not exist, client-error-not-found is returned.
The following group of attributes is supplied as part of the CUPS-Get-PPD request:
Group 1: Operation Attributes
The following group of attributes is sent as part of the CUPS-Get-PPD Response:
Group 1: Operation Attributes
If the status code is successful-ok, the PPD file follows the end of the IPP response.
The CUPS-Get-Document operation (0x4027) gets a document file from a job on the server. The document file is specified using the document-number and either the job-uri or printer-uri and job-id identifying the job.
If the document file is found, successful-ok is returned with the document file following the response data.
If the document file does not exist, client-error-not-found is returned.
If the requesting user does not have access to the document file, client-error-not-authorized is returned.
The following group of attributes is supplied as part of the CUPS-Get-Document request:
Group 1: Operation Attributes
The following group of attributes is sent as part of the CUPS-Get-Document Response:
Group 1: Operation Attributes
If the status code is successful-ok, the document file follows the end of the IPP response.
The CUPS-Create-Local-Printer operation (0x4028) creates a local (temporary) print queue pointing to a remote IPP Everywhere Printer. The queue will remain until the scheduler idle exits, is restarted, or the system is restarted or shutdown. Temporary print queues can be made permanent by an administrator by setting the "printer-is-shared" attribute to 'true'.
At a minimum, the scheduler requires a name and URI for the Printer to add. When successful, the local "printer-uri" values are returned and may be used by the Client to submit Job Creation Requests, monitor for state changes, and so forth.
If the named printer already exists, the scheduler will reject the request with the 'client-error-not-possible' status code.
Access Rights: The authenticated user performing this operation MUST be a Local User of the system, and the request MUST be made over a local (domain socket or loopback interface) address. Otherwise, the request will be rejected with the 'client-error-forbidden' status code.
The following group of attributes is supplied as part of the CUPS-Create-Local-Printer request:
Group 1: Operation Attributes
Group 2: Printer Attributes
The following group of attributes is sent as part of the CUPS-Create-Local-Printer Response:
Group 1: Operation Attributes
Group 2: Printer Attributes
CUPS provides many extension attributes to support multiple devices, PPD files, standard job filters, printers, and printer classes.
Device attributes are returned by the CUPS-Get-Devices operation and enumerate all of the available hardware devices and network protocols that are supported by the server. Device attributes are reported in the printer-attributes-tag group.
The "device-class" attribute provides the class of device and can be one of the following:
The "device-id" attribute provides the IEEE-1284 device ID string for the device.
The "device-info" attribute specifies a human-readable string describing the device, e.g., 'Parallel Port #1'.
The "device-location" attribute specifies the physical location of the printer, e.g., '2nd Floor Computer Lab'.
The "device-make-and-model" attribute specifies a device identification string provided by the printer connected to the device. If the device or printer does not support identification then this attribute contains the string 'unknown'.
The "device-uri" attribute specifies a unique identifier for the device. The actual format of the "device-uri" string depends on the value of the "device-class" attribute:
The URI returned by CUPS-Get-Devices will contain the maximum baud rate supported by the device and the best type of flow control available ("soft" or "hard").
The URI returned by CUPS-Get-Devices MAY only contain the scheme name ('scheme'). It is up to the client application to add the appropriate host and other information when adding a new printer.
The URI returned by Get-Printer-Attributes and CUPS-Get-Printers has any username and password information stripped; the information is still stored and used by the server internally to perform any needed authentication.
The "auth-info" attribute specifies the authentication information to use when printing to a remote device. The order and content of each text value is specifed by the auth-info-required printer attribute.
The "job-cancel-after" attribute provides the maximum number of seconds that are allowed for processing a job.
The "job-hold-until" attribute specifies a hold time. In addition to the standard IPP/1.1 keyword names, CUPS supports name values of the form "HH:MM" and "HH:MM:SS" that specify a hold time. The hold time is in Universal Coordinated Time (UTC) and not in the local time zone. If the specified time is less than the current time, the job is held until the next day.
The "job-media-progress" status attribute specifies the percentage of completion of the current page. It is only valid when the "job-state" attribute has the 'processing(5)' value.
The "job-printer-state-message" status attribute provides the last known value of the "printer-state-message" attribute for the printer that processed (or is processing) the job.
The "job-printer-state-reasons" status attribute provides the last known value of the "printer-state-reasons" attribute for the printer that processed (or is processing) the job.
The "job-sheets" attribute specifies one or two banner files that are printed before and after a job. The reserved value of "none" disables banner printing. The default value is stored in the "job-sheets-default" attribute.
If only one value is supplied, the banner file is printed before the job. If two values are supplied, the first value is used as the starting banner file and the second as the ending banner file.
The "job-originating-host-name" status attribute specifies the host from which the job was queued. The value will be the hostname or IP address of the client depending on whether hostname resolution is enabled. The localhost address (127.0.0.1) is always resolved to the name "localhost".
This attribute is read-only.
The "page-border" attribute specifies whether a border is draw around each page. The following keywords are presently defined:
The "page-set" attribute specifies which pages to print in a file. The supported keywords are 'all', 'even', and 'odd'. The default value is 'all'.
PPD attributes are returned in the printer-attributes-tag group.
The "ppd-device-id" attribute specifies the IEEE-1284 device ID string for the device described by the PPD file.
The "ppd-make" attribute specifies the manufacturer of the printer (the Manufacturer attribute in the PPD file). If the manufacturer is not specified in the PPD file then an educated guess is made using the NickName attribute in the PPD file.
The "ppd-make-and-model" attribute specifies the manufacturer and model name of the PPD file (the NickName attribute in the PPD file). If the make and model is not specified in the PPD file then the ModelName or ShortNickName attributes are used instead.
The "ppd-model-number" attribute provides the cupsModelNumber value from the PPD file.
The "ppd-name" attribute specifies either the PPD filename on the server relative to the model directory or a URI that maps to a specific driver interface in the driver directory. The forward slash (/) is used to delineate directories.
The "ppd-natural-language" attribute specifies the language encoding of the PPD file (the LanguageVersion attribute in the PPD file). If the language is unknown or undefined then "en" (English) is assumed.
The "ppd-product" attribute specifies the Product attribute values in the PPD file.
The "ppd-product" attribute specifies the PSVersion attribute values in the PPD file.
The "ppd-type" attribute specifies the type of driver described by the PPD file:
The "auth-info-required" attribute specifies the authentication information that is required for printing a job. The following keywords are recognized:
The "job-k-limit" attribute specifies the maximum number of kilobytes that may be printed by a user, including banner files. The default value of 0 specifies that there is no limit.
The "job-page-limit" attribute specifies the maximum number of pages that may be printed by a user, including banner files. The default value of 0 specifies that there is no limit.
The "job-quota-period" attribute specifies the time period used for quota calculations, in seconds. The default value of 0 specifies that the limits apply to all jobs that have been printed by a user that are still known to the system.
The "marker-change-time" status attribute specifies the "printer-up-time" value when the last change to the marker-colors, marker-levels, marker-message, marker-names, or marker-types attributes was made.
The "marker-colors" status attribute specifies the color(s) for each supply in the printer. It is only available when the driver provides supply levels. The color is either 'none' or one or more hex-encoded sRGB colors of the form '#RRGGBB'.
The "marker-high-levels" status attribute specifies the supply levels that indicate a near-full condition. A value of 100 should be used for supplies that are consumed/emptied, e.g. ink cartridges.
The "marker-levels" status attribute specifies the current supply levels for the printer. It is only available when the driver provides supply levels. A value of -1 indicates the level is unavailable, -2 indicates unknown, and -3 indicates the level is unknown but has not yet reached capacity. Values from 0 to 100 indicate the corresponding percentage.
The "marker-low-levels" status attribute specifies the supply levels that indicate a near-empty condition. A value of 0 should be used for supplies that are filled, e.g. waste ink tanks.
The "marker-message" status attribute provides a human-readable status message for the current supply levels, e.g. "12 pages of ink remaining." It is only available when the driver provides supply levels.
The "marker-names" status attribute specifies the name(s) for each supply in the printer. It is only available when the driver provides supply levels.
The "marker-types" status attribute specifies the type(s) of each supply in the printer. It is only available when the driver provides supply levels. The following (RFC 3805) types are currently supported:
The "port-monitor" attribute specifies the port monitor to use when printing to this printer. The default port monitor is 'none'.
The "port-monitor-supported" attribute specifies the available port monitors.
The "printer-commands" attribute specifies the commands that are supported by the CUPS command file filter. The keyword 'none' indicates that no commands are supported.
The "printer-dns-sd-name" attribute specifies the registered DNS-SD service name for the printer. If the printer is not being shared using this protocol, "printer-dns-sd-name" will have the no-value value.
The "printer-id" status attribute provides a unique integer identifying the printer. It is used when only an IP address and integer are provided for identifying a print queue.
The "printer-type" status attribute specifies printer type and capability bits for the printer or class. The default value is computed from internal state information and the PPD file for the printer. The following bits are defined:
| Bit | Description |
|---|---|
| 0x00000001 | Is a printer class. |
| 0x00000002 | Is a remote destination. |
| 0x00000004 | Can print in black. |
| 0x00000008 | Can print in color. |
| 0x00000010 | Can print on both sides of the page in hardware. |
| 0x00000020 | Can staple output. |
| 0x00000040 | Can do fast copies in hardware. |
| 0x00000080 | Can do fast copy collation in hardware. |
| 0x00000100 | Can punch output. |
| 0x00000200 | Can cover output. |
| 0x00000400 | Can bind output. |
| 0x00000800 | Can sort output. |
| 0x00001000 | Can handle media up to US-Legal/A4. |
| 0x00002000 | Can handle media from US-Legal/A4 to ISO-C/A2. |
| 0x00004000 | Can handle media larger than ISO-C/A2. |
| 0x00008000 | Can handle user-defined media sizes. |
| 0x00010000 | Is an implicit (server-generated) class. |
| 0x00020000 | Is the a default printer on the network. |
| 0x00040000 | Is a facsimile device. |
| 0x00080000 | Is rejecting jobs. |
| 0x00100000 | Delete this queue. |
| 0x00200000 | Queue is not shared. |
| 0x00400000 | Queue requires authentication. |
| 0x00800000 | Queue supports CUPS command files. |
| 0x01000000 | Queue was automatically discovered and added. |
| 0x02000000 | Queue is a scanner with no printing capabilities. |
| 0x04000000 | Queue is a printer with scanning capabilities. |
| 0x08000000 | Queue is a printer with 3D capabilities. |
The "printer-type-mask" attribute is used to choose printers or classes with the CUPS-Get-Printers and CUPS-Get-Classes operations. The bits are defined identically to the printer-type attribute and default to all 1's.
The "requesting-user-name-allowed" attribute lists all of the users that are allowed to access a printer or class. Either this attribute or the "requesting-user-name-denied" attribute will be defined, but not both.
The "requesting-user-name-denied" attribute lists all of the users that are not allowed to access a printer or class. Either this attribute or the "requesting-user-name-allowed" attribute will be defined, but not both.
Printer class attributes are placed in the printer-attributes-tag group.
The "member-names" attribute specifies the "printer-name" attributes for each the member printer and class. Each name corresponds to the same element of the "member-uris" attribute.
The "member-uris" attribute specifies the "printer-uri-supported" values for each member printer and class. Each URI corresponds to the same element of the "member-names" attribute.