8.11. Built-in Module syslog

The module defines the following functions:

syslog ([priority,] message) -- Method on posixfile

Send the string message to the system logger. A trailing newline is added if necessary. Each message is tagged with a priority composed of a facility and a level. The optional priority argument, which defaults to (LOG_USER | LOG_INFO), determines the message priority.

openlog (ident, [logopt, [facility]]) -- Method on posixfile

Logging options other than the defaults can be set by explicitly opening the log file with openlog() prior to calling syslog(). The defaults are (usually) ident = `syslog', logopt = 0, facility = LOG_USER. The ident argument is a string which is prepended to every message. The optional logopt argument is a bit field - see below for possible values to combine. The optional facility argument sets the default facility for messages which do not have a facility explicitly encoded.

closelog () -- Method on posixfile

Close the log file.

setlogmask (maskpri) -- Method on posixfile

This function set the priority mask to maskpri and returns the previous mask value. Calls to syslog with a priority level not set in maskpri are ignored. The default is to log all priorities. The function LOG_MASK(pri) calculates the mask for the individual priority pri. The function LOG_UPTO(pri) calculates the mask for all priorities up to and including pri.

Priority levels (high to low):

LOG_EMERG, LOG_ALERT, LOG_CRIT, LOG_ERR, LOG_WARNING, LOG_NOTICE, LOG_INFO, LOG_DEBUG.

Facilities:

LOG_KERN, LOG_USER, LOG_MAIL, LOG_DAEMON, LOG_AUTH, LOG_LPR, LOG_NEWS, LOG_UUCP, LOG_CRON and LOG_LOCAL0 to LOG_LOCAL7.

Log options:

LOG_PID, LOG_CONS, LOG_NDELAY, LOG_NOWAIT and LOG_PERROR if defined in syslog.h.