Translating and Customizing CUPS

Translating and Customizing CUPS

Thanks to its extensive use of templates, images, and message catalogs, CUPS can be easily translated (or customized!) to suit your needs. This help file will guide you through the CUPS localization files so you can get the most out of it.

Getting Started

Start by downloading the CUPS source code from www.cups.org. After you extract the files from the source archive, you will want to copy the following files and directories:

With the exception of the message catalogs and desktop file, localization files are placed in subdirectories under the doc and templates using the locale name. Locale names are either ll or ll_CC, where "ll" is the 2-letter language code and "CC" is the 2-letter country code. CUPS does not currently use or support the newer ll-region syntax for locale names.

All non-image files must be encoded using the UTF-8 character set.

Submitting a Translation for CUPS

To submit a translation for inclusion in CUPS, translate the desktop file, all of the template files, the index.html.in file, and the message catalog. Place these files in the correct subdirectories in the CUPS source code archive and run the following command to create an archive with your files:

tar cvf ll_CC.tar.gz desktop/cups.desktop doc/ll_CC \
    locale/cups_ll_CC.po templates/ll_CC

Replace "ll_CC" with the locale name for your translation. Once you have created the archive, go to the CUPS Bugs & Features page and submit a bug report, attaching the translation to the report.

The Desktop File

The desktop/cups.desktop file provides a link to the CUPS web interface from desktop environments such as GNOME and KDE. To translate this file, add two lines to the bottom with the Name and Comment keys:

Name[ll_CC]=Translation of "Manage Printing"
Comment[ll_CC]=Translation of "CUPS Web Interface"

The Home Page

The index.html file is a complete HTML file that is displayed when the user visits "http://localhost:631/". Edit the existing doc/index.html and save it in the doc/ll_CC subdirectory so that the makefile can install it. Run "make install" in the doc subdirectory to test the new home page.

Message Catalogs

CUPS message catalogs are GNU gettext ".po" text files that provide a list of localized message strings for the CUPS software. Message catalogs are named cups_ll.po or cups_ll_CC.po, where "ll" is the standard 2-letter abbreviation for the language and "CC" is the standard 2-letter abbreviation for the country.

When translating a new message catalog, copy the cups.pot message catalog file in the locale subdirectory of the CUPS source code. For example, to start translating the message catalog to Canadian French, you would type the following commands:

cd locale
cp cups.pot cups_fr_CA.po

Alternatively, you can copy the existing cups_fr.po message catalog and then make any necessary changes.

Once you have make your copy of the file, edit it using your favorite text editor or translation program to translate the text to the desired language.

Then validate your translation using the locale/checkpo utility:

cd locale
./checkpo cups_ll_CC.po

After fixing any errors in your translation, add your locale to the LANGUAGES variable in the Makedefs file and run the "make install" command in the locale subdirectory to test the translation.

Template Files

The CUPS scheduler provides a web interface that can be used to do many common printing and administration tasks. The built-in web server supports localization of web pages through the use of subdirectories for each locale, e.g. "fr" for French, "de" for German, "fr_ca" for French in Canada, and so forth.

Template files are HTML files with special formatting characters in them that allow substitution of variables and arrays. The CUPS CGI programs (admin.cgi, classes.cgi, help.cgi, jobs.cgi, and printers.cgi) use these template file to provide dynamic content for the web interface. Template files are installed in the /usr/share/cups/templates directory by default. Table 2 lists the various template files and their purpose.

Translated versions of the template files should be saved in the templates/ll_CC subdirectory. For example, Canadian French template files should be saved in the templates/fr_CA subdirectory. After you have translated all of the templates, add the locale to the LANGUAGES variable in the Makedefs file and run "make install" in the templates subdirectory to test the translation.

Table 2: Web Interface Template Files
Filename Purpose
add-class.tmpl This is the initial form that is shown to add a new printer class.
add-printer.tmpl This is the initial form that is shown to add a new printer.
add-rss-subscription.tmpl This is the form that is shown to add a new RSS subscription.
admin.tmpl This is the main administration page.
choose-device.tmpl This is the form that shows the list of available devices.
choose-make.tmpl This is the form that shows the list of available manufacturers.
choose-model.tmpl This is the form that shows the list of available printer models/drivers.
choose-serial.tmpl This is the form that allows the user to choose a serial port and any options.
choose-uri.tmpl This is the form that allows the user to enter a device URI for network printers.
class-added.tmpl This template shows the "class added" message.
class-confirm.tmpl This is the template used to confirm the deletion of a class.
class-deleted.tmpl This template shows the "class deleted" message.
class-jobs-header.tmpl This template shows the "jobs" header for jobs in a class.
class-modified.tmpl This template shows the "class modified" message.
classes.tmpl This template shows one or more printer classes.
classes-header.tmpl This template shows the "showing N of M classes" header in the class list.
edit-config.tmpl This is the cupsd.conf editor page.
error.tmpl This template displays a generic error message.
error-op.tmpl This is the "unknown operation" error page.
header.tmpl This template is used as the standard header on all dynamic content.
help-header.tmpl This is the top part of the help page.
help-printable.tmpl This is the standard page header for the printable version of help files.
job-cancel.tmpl This template shows "job canceled".
job-hold.tmpl This template shows "job held".
job-move.tmpl This template shows the move-job form.
job-moved.tmpl This template shows "job moved".
job-release.tmpl This template shows "job released".
job-restart.tmpl This template shows "job reprinted".
jobs.tmpl This template is used to list the print jobs on a server, class, or printer.
jobs-header.tmpl This template shows the "showing N or M jobs" header in the jobs list.
list-available-printers.tmpl This template shows a list of new printers that have been found.
maintenance.tmpl This template shows "maintenance commands sent".
modify-class.tmpl This template is used as the first form when modifying a class.
modify-printer.tmpl This template is used as the first form when modifying a printer.
norestart.tmpl This template shows "server not restarted because no changes were made to the configuration".
option-boolean.tmpl This template is used to select a boolean PPD option.
option-conflict.tmpl This template shows the conflicting options.
option-header.tmpl This template is used to start a PPD option group.
option-pickmany.tmpl This template is used to select a multi-valued PPD option.
option-pickone.tmpl This template is used to select a single-valued PPD option.
option-trailer.tmpl This template is used to end a PPD option group.
pager.tmpl This template shows the previous/next pager bar.
printer-accept.tmpl This template shows "printer now accepting jobs".
printer-added.tmpl This template shows "printer added".
printer-configured.tmpl This template shows "printer configured".
printer-confirm.tmpl This template asks the user to confirm the deletion of a printer.
printer-default.tmpl This template shows "default printer set".
printer-deleted.tmpl This template shows "printer deleted".
printer-jobs-header.tmpl This templates shows the "jobs" header for jobs on a printer.
printer-modified.tmpl This template shows "printer modified".
printer-purge.tmpl This template shows "printer has been purged of all jobs".
printer-reject.tmpl This template shows "printer now rejecting jobs".
printer-start.tmpl This template shows "printer started".
printer-stop.tmpl This template shows "printer stopped".
printers.tmpl This template is used to list information on one or more printers.
printers-header.tmpl This template shows the "showing printer N of M" header in the printers list.
restart.tmpl This template shows "server restarting".
samba-export.tmpl This template shows the export printers to Samba form.
samba-exported.tmpl This template shows "printers exported to Samba".
search.tmpl This template shows the search form.
set-printer-options-header.tmpl This template shows the first part of the set printer options form.
set-printer-options-trailer.tmpl This template shows the last part of the set printer options form.
subscription-added.tmpl This template shows "subscription ... added".
subscription-canceled.tmpl This template shows "subscription #NNN canceled".
test-page.tmpl This template shows "test page printed".
trailer.tmpl This template is used as the standard trailer on all dynamic content.
users.tmpl This template shows the set allowed users form.

Inserting Attributes and Values

Template files consist of HTML with variable substitutions for named inside curly braces "{name}". Variable names are generally the IPP attribute names with the hyphen ("-") replaced by the underscore ("_") character. For example, the job-printer-uri attribute is renamed to job_printer_uri.

Curley braces ("{" and "}") to indicate substitutions, and the backslash ("\") character for quoting. To insert any of these special characters as-is you need to use the HTML &name; mechanism or prefix each special character with the backslash ("\".)

You substitute the value of a variable using {NAME} in your template file. If the variable is undefined then the {NAME} string is output as-is.

To substitute an empty string if the variable is undefined, use {?NAME} instead.

Array Substitutions

The number of array elements can be inserted using {#NAME}. If the array is undefined then 0 is output. The current array element (starting at 1) is inserted with {#}.

Arrays are handled using {[NAME] at the beginning of a section and } at the end. The information between the closing bracket ("]") and closing brace ("}") is repeated for as many elements as are in the named array. For example, the following template will display a list of each job in the job_id array:

<TABLE>
<TR>
	<TH>Job ID</TH>
	<TH>Destination</TH>
	<TH>Title</TH>
</TR>

{[job_id]
<TR>
	<TD>{?job_id}</TD>
	<TD>{?job_printer_name}</TD>
	<TD>{?job_name}</TD>
</TR>
}
</TABLE>

Arrays can be nested, however all elements within the curly braces ("{" and "}") are indexed using the innermost array.

Conditional Tests

Templates can also test variables against specific values and conditionally include text in the template. The format is:

{variable?true:false}
{variable=value?true:false}
{variable!value?true:false}
{variable<value?true:false}
{variable>value?true:false}

where true is the text that is included if the condition is true and false is the text that is included if the condition is false. A value of # is replaced with the current element number (starting at 1.) The character after the variable name specifies the condition to test. Table 3 shows the available test conditions.

Table 3: Template Substitution Conditions
Char Condition
? True if variable exists.
= True if variable is equal to value.
! True if variable is not equal to value.
< True if variable is less than value.
> True if variable is greater than value.

CGI Programs

CUPS uses five CGI programs to manage the dynamic web interfaces:

Each CGI program accepts standard form variables such as OP for the operation to perform, PRINTER_NAME for the printer or class name to operate on, QUERY for any search words, FIRST for the first class, job, or printer to display, and ORDER to control the order that classes, jobs, or printers are displayed.

In addition, the classes.cgi, jobs.cgi, and printers.cgi programs support a WHICH_JOBS variable to control which jobs are displayed. Table 4 lists the supported values.

Table 4: WHICH_JOBS Values
WHICH_JOBS Value Description
all Show all jobs
completed Show completed jobs
not-completed Show active jobs

admin.cgi

The admin.cgi program handles all of the printer and class administration functions and is run for all direct accesses to the /admin resource. For most operations it uses the PRINTER_NAME and OP form variables to specify the action requested. Table 5 shows the supported OP values.

Table 5: admin.cgi OP Values
OP Value Description
accept-jobs Accepts jobs on the named destination.
add-class Adds a new printer class.
add-printer Adds a new printer.
config-server Configures the server.
delete-class Deletes a printer class. The form variable CONFIRM may be set to any value to bypass the confirmation page.
delete-printer Deletes a printer. The form variable CONFIRM may be set to any value to bypass the confirmation page.
export-samba Exports printers to Samba.
find-new-printers Find new printers that have not yet been added.
modify-class Modifies a printer class.
modify-printer Modifies a printer.
purge-jobs Purges all jobs on the named destination.
redirect Redirects the web browser to the location referenced by the URL form variable.
reject-jobs Rejects new jobs on the named destination.
set-allowed-users Sets the allowed users for a destination.
set-as-default Sets the default destination.
set-printer-options Sets the default options for a printer.
set-sharing Sets the printer-is-shared attribute for a destination.
start-class Starts the named class.
start-printer Starts the named printer.
stop-class Stops the named class.
stop-printer Stops the named printer.

classes.cgi

The classes.cgi program is responsible for listing class information, including jobs destined for that class. It is for all direct accesses to the /classes resource and supports the optional form variables OP and WHICH_JOBS. If no form variables are supplied then the CGI lists all or a specific class and the active jobs on each class. Table 6 shows the supported OP values.

Table 6: classes.cgi OP Values
OP Value Description
move-jobs Moves the jobs on this class to another destination.
print-test-page Prints the standard PostScript test page.

help.cgi

The help.cgi program handles all of the on-line help functions and is run for all direct accesses to the /help resource.

jobs.cgi

The jobs.cgi program handles all of the job functions and is run for all direct accesses to the /jobs resource. For most operations it uses the JOB_ID, OP, and WHICH_JOBS form variables to specify the action requested. Table 7 shows the supported OP values.

Table 7: jobs.cgi OP Values
OP Value Description
cancel-job Cancels a job.
hold-job Holds a job indefinitely.
move-job Moves a job to another destination.
release-job Releases a job for printing.
restart-job Restarts/reprints a stopped, canceled, completed, or aborted print job.

printers.cgi

The printers.cgi program is responsible for listing printer information, including jobs destined for that printer. It is for all direct accesses to the /printers resource and supports the optional form variables OP and WHICH_JOBS. If no form variables are supplied then the CGI lists all printers or a specific printer and the active jobs on that printer. Table 8 shows the supported OP values.

Table 8: printers.cgi OP Values
OP Value Description
clean-print-heads Clean the print heads.
move-jobs Move all jobs to a different destination.
print-self-test-page Print a printer self-test page.
print-test-page Print a PostScript test page.