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Configuration file for syslogd




The /etc/syslog.conf file is the configuration file for the syslogd daemon. It consists of lines with two fields:

Selector field
The types of messages and priorities to which the line applies.
Action field
The action to take if a message received by syslogd matches the selection criteria.

The selector field is separated from the action field by one or more tab characters.

The selectors are encoded as a facility, a dot ("."), and a level, with no intervening whitespace. Both the facility and the level are case insensitive.

The facility describes the part of the system generating the message, and is one of the following keywords:

These keywords (with the exception of mark) correspond to the similar "LOG_" values specified to the openlog() and syslog() routines.

The level describes the severity of the message, and is a keyword from the following ordered (higher to lower) list:

These keywords also correspond to the similar "LOG_" values specified to the syslog() routine.

For further descriptions of both the facility and level keywords and their significance, see syslog() in the Library Reference.

If a received message matches the specified facility and is of the specified (or a higher) level, then the action specified in the action field is taken.

Multiple selectors may be specified for a single action by separating them with semicolon (;) characters.

Note: Note that each selector can modify the ones preceding it.

You can specify multiple facilities for a single level by separating them with comma (,) characters.

You can use an asterisk (*) to specify all facilities or all levels.

The special facility mark receives a message at priority info every 20 minutes (see syslogd).

The special level none disables a particular facility.

The action field of each line specifies the action to be taken when the selector field selects a message. The action field can take these forms:

Blank lines and lines whose first nonblank character is a hash (#) character are ignored.


A configuration file might appear as follows:

# Log all kernel messages, authentication messages of
# level notice or higher and anything of level err or
# higher to the console.
# Don't log private authentication messages!
*.err;kern.*;auth.notice;authpriv.none /dev/console

# Log anything (except mail) of level info or higher.
# Don't log private authentication messages!
*.info;mail.none;authpriv.none         /var/log/messages

# The authpriv file has restricted access.
authpriv.*                             /var/log/secure

# Log all the mail messages in one place.
mail.*                                 /var/log/maillog

# Everybody gets emergency messages, plus log them on
# another machine.
*.emerg                    *

# Root and Eric get alert and higher messages.
*.alert                    root,eric

# Save mail and news errors of level err and higher in a
# special file.
uucp,news.crit             /var/log/spoolerr


The effects of multiple selectors aren't always intuitive. For example, mail.crit,*.err selects mail facility messages at the level of err or higher, not at the level of crit or higher.

Logging messages to users isn't currently implemented.

See also:


openlog(), syslog() in the Library Reference