Notifiers must read IPP messages from the standard input using the ippNew and ippReadFile functions and exit on error. Notifiers are encouraged to exit after a suitable period of inactivity, however they may exit after reading the first message or stay running until an error is seen.
ALERT: message
Sets the printer-state-message attribute and adds the specified
message to the current ErrorLog using the "alert" log level.
CRIT: message
Sets the printer-state-message attribute and adds the specified
message to the current ErrorLog using the "critical" log level.
DEBUG: message
Sets the printer-state-message attribute and adds the specified
message to the current ErrorLog using the "debug" log level.
DEBUG2: message
Sets the printer-state-message attribute and adds the specified
message to the current ErrorLog using the "debug2" log level.
EMERG: message
Sets the printer-state-message attribute and adds the specified
message to the current ErrorLog using the "emergency" log level.
ERROR: message
Sets the printer-state-message attribute and adds the specified
message to the current ErrorLog using the "error" log level.
INFO: message
Sets the printer-state-message attribute. If the current LogLevel
is set to "debug2", also adds the specified message to the
current ErrorLog using the "info" log level.
NOTICE: message
Sets the printer-state-message attribute and adds the specified
message to the current ErrorLog using the "notice" log level.
WARNING: message
Sets the printer-state-message attribute and adds the specified
message to the current ErrorLog using the "warning" log level.
CHARSET
The default text character set, typically utf-8.
CUPS_CACHEDIR
The directory for semi-persistent cache files can be found.
CUPS_DATADIR
The directory where data files can be found.
CUPS_FILETYPE
The type of file being printed: "job-sheet" for a banner page and "document"
for a regular print file.
CUPS_SERVERROOT
The root directory of the server.
LANG
The default language locale (typically C or en).
PATH
The standard execution path for external programs that may be run by
the filter.
SOFTWARE
The name and version number of the server (typically CUPS/1.2).
TZ
The timezone of the server.
USER
The user executing the filter, typically "lp"; consult the cupsd.conf(5)
file for the current setting.