.\"
.\" "$Id: filter.man 6649 2007-07-11 21:46:42Z mike $"
.\"
.\"   filter man page for the Common UNIX Printing System (CUPS).
.\"
.\"   Copyright 2007 by Apple Inc.
.\"   Copyright 1997-2007 by Easy Software Products.
.\"
.\"   These coded instructions, statements, and computer programs are the
.\"   property of Apple Inc. and are protected by Federal copyright
.\"   law.  Distribution and use rights are outlined in the file "LICENSE.txt"
.\"   which should have been included with this file.  If this file is
.\"   file is missing or damaged, see the license at "http://www.cups.org/".
.\"
.TH filter 7 "Common UNIX Printing System" "6 July 2007" "Apple Inc."
.SH NAME
filter \- cups file conversion filter interface
.SH SYNOPSIS
.B filter
job user title num-copies options [
.I filename
]
.SH DESCRIPTION
The CUPS filter interface provides a standard method for adding support for
new document types to CUPS. Each filter is capable of converting from one
or more input formats to another format that can either be printed directly
or piped into another filter to get it to a printable format.
.LP
Filters \fBmust\fR be capable of reading from a filename on the command-line
or from the standard input, copying the standard input to a temporary
file as required by the file format. All output \fBmust\fR be sent to the
standard output.
.LP
The command name (argv[0]) is set to the name of the destination printer.
.SH LOG MESSAGES
Messages sent to stderr are generally logged to
printer-state-message attribute and the current \fIErrorLog\fR.
Each line begins with a standard prefix:

.TP 5
ALERT: message
.br
Sets the printer-state-message attribute and adds the specified
message to the current \fIErrorLog\fR using the "alert" log level.

.TP 5
ATTR: attribute=value [attribute=value]
.br
Sets the named job attribute(s). Typically this will be used to
set the job-remote-id attribute.

.TP 5
CRIT: message
.br
Sets the printer-state-message attribute and adds the specified
message to the current \fIErrorLog\fR using the "critical" log level.

.TP 5
DEBUG: message
.br
Sets the printer-state-message attribute and adds the specified
message to the current \fIErrorLog\fR using the "debug" log level.

.TP 5
DEBUG2: message
.br
Sets the printer-state-message attribute and adds the specified
message to the current \fIErrorLog\fR using the "debug2" log level.

.TP 5
EMERG: message
.br
Sets the printer-state-message attribute and adds the specified
message to the current \fIErrorLog\fR using the "emergency" log level.

.TP 5
ERROR: message
.br
Sets the printer-state-message attribute and adds the specified
message to the current \fIErrorLog\fR using the "error" log level.

.TP 5
INFO: message
.br
Sets the printer-state-message attribute. If the current \fILogLevel\fR
is set to "debug2", also adds the specified message to the
current \fIErrorLog\fR using the "info" log level.

.TP 5
NOTICE: message
.br
Sets the printer-state-message attribute and adds the specified
message to the current \fIErrorLog\fR using the "notice" log level.

.TP 5
PAGE: page-number #-copies
.TP 5
PAGE: total #-pages
.br
Adds an entry to the current \fIPageLog\fR. The first form adds
#-copies to the job-media-sheets-completed attribute. The second
form sets the job-media-sheets-completed attribute to #-pages.

.TP 5
STATE: printer-state-reason [printer-state-reason ...]
.TP 5
STATE: + printer-state-reason [printer-state-reason ...]
.TP 5
STATE: - printer-state-reason [printer-state-reason ...]
.br
Sets, adds, or removes printer-state-reason keywords to the
current queue. Typically this is used to indicate media, ink, and
toner conditions on a printer.

.TP 5
WARNING: message
.br
Sets the printer-state-message attribute and adds the specified
message to the current \fIErrorLog\fR using the "warning" log level.

.SH ENVIRONMENT VARIABLES
The following environment variables are defined by the CUPS
server when executing the filter:

.TP 5
CHARSET
.br
The default text character set, typically utf-8.

.TP 5
CLASS
.br
When a job is submitted to a printer class, contains the name of
the destination printer class. Otherwise this environment
variable will not be set.

.TP 5
CONTENT_TYPE
.br
The MIME type associated with the file (e.g.
application/postscript).

.TP 5
CUPS_DATADIR
.br
The directory where data files can be found.

.TP 5
CUPS_SERVERROOT
.br
The root directory of the server.

.TP 5
DEVICE_URI
.br
The device-uri associated with the printer.

.TP 5
FINAL_CONTENT_TYPE
.br
The MIME type associated with the printer (e.g.
application/vnd.cups-postscript).

.TP 5
LANG
.br
The default language locale (typically C or en).

.TP 5
PATH
.br
The standard execution path for external programs that may be run by
the filter.

.TP 5
PPD
.br
The full pathname of the PostScript Printer Description (PPD)
file for this printer.

.TP 5
PRINTER
.br
The name of the printer.

.TP 5
RIP_CACHE
.br
The recommended amount of memory to use for Raster Image
Processors (RIPs).

.TP 5
SOFTWARE
.br
The name and version number of the server (typically CUPS/1.2).

.TP 5
TZ
.br
The timezone of the server.

.TP 5
USER
.br
The user executing the filter, typically "lp" or "root"; consult the
\fIcupsd.conf(5)\fR file for the current setting.

.SH COMPATIBILITY
While the filter interface is compatible with System V interface
scripts, it will only work with the System V interface script as the
only filter.  Typically the interface script will be provided via the
\fIlpadmin(8)\fR command using the \fI-i\fR option.
.SH SEE ALSO
\fIbackend(1)\fR, \fIcupsd(8)\fR,
.br
http://localhost:631/help
.SH COPYRIGHT
Copyright 2007 by Apple Inc.
.\"
.\" End of "$Id: filter.man 6649 2007-07-11 21:46:42Z mike $".
.\"