The selector field is encoded as a facility, a period (``.''), and a level , with no intervening white-space. 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: auth, cron, daemon and kern. Here's a short description of each facility keyword:
Messages generated by the filer kernel.
System daemons, such as the
rshd daemon (see na_rshd(8)), the routing daemon
(see na_routed(1)), the SNMP daemon (see
na_snmpd(8)), etc.
The authentication system, e.g. messages logged for Telnet sessions.
The system's internal cron facility.
The level describes the severity of the message, and is a keyword from the following ordered list (higher to lower): emerg, alert, crit, err, warning, notice, info, and debug.
Here is a short description of each level keyword:
A panic condition that results in the disruption of normal service.
A condition that should be corrected immediately, such as a failed disk.
Critical conditions, such as hard disk errors.
Errors, such as those resulting from a bad configuration file.
Warning messages.
Conditions that are not error conditions, but that may require special handling.
Informational messages, such as the hourly uptime message (see na_uptime(1)).
Debug messages used for diagnostic purposes. These messages are supressed by default.
If a received message matches the specified facility and is of the specified level (or a higher level ), the action specified in the action field will be taken.
Multiple selectors may be specified for a single action by separating them with semicolon (``;'') characters. It is important to note, however, that each selector can modify the ones preceding it.
Multiple facilities may be specified for a single level by separating them with comma (``,'') characters.
An asterisk (``*'') can be used to specify all facilities or all levels .
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. There are four forms:
A pathname (beginning with a leading slash). Selected messages are appended to the specified file.
A hostname (preceded by an at (``@'') sign). Selected messages are forwarded to the syslogd daemon on the named host.
/dev/console. Selected messages are written to the console.
An asterisk. Selected messages are written to the console.
Blank lines and lines whose first non-blank character is a pound (``#'') character are ignored.
It is recommended that all /etc/syslog.conf files include the line
*.info /etc/messages
so that all messages are logged to the /etc/messages file.
A configuration file might appear as follows:
# Log all kernel messages, and anything of level err or # higher to the console. *.err;kern.* /dev/console # Log anything of level info or higher to /etc/messages. *.info /etc/messages # Also log the messages that go to the console to a remote # loghost system called adminhost. *.err;kern.* @adminhost # The /etc/secure.message file has restricted access. auth.notice /etc/secure.message