SYSLOG.CONF(4) File Formats and Configurations SYSLOG.CONF(4)


NAME


syslog.conf - configuration file for syslogd system log daemon

SYNOPSIS


/etc/syslog.conf


DESCRIPTION


The file /etc/syslog.conf contains information used by the system log
daemon, syslogd(1M), to forward a system message to appropriate log files
and/or users. syslogd preprocesses this file through m4(1) to obtain the
correct information for certain log files, defining LOGHOST if the
address of "loghost" is the same as one of the addresses of the host that
is running syslogd.


A configuration entry is composed of two TAB-separated fields:

selector action


The selector field contains a semicolon-separated list of priority
specifications of the form:

facility.level [ ; facility.level ]


where facility is a system facility, or comma-separated list of
facilities, and level is an indication of the severity of the condition
being logged. The presence of a facility name only implies that it is
available. Each individual service determines which facility it will use
for logging. In particular, many facilities are only useful for syslog
messages that are forwarded from other operating systems. Recognized
values for facility include:

kern
Messages generated by the kernel.


user
Messages generated by user processes. This is the default
priority for messages from programs or facilities not listed
in this file.


mail
The mail system.


daemon
Various system daemons.


auth
The authorization system: login(1), su(1M), getty(1M), among
others.


lpr
The line printer spooling system: lpr(1B), lpc(1B), among
others.


news
Designated for the USENET network news system.


uucp
Designated for the UUCP system; it does not currently use the
syslog mechanism.


altcron
Designated for the BSD cron/at system.


authpriv
Designated for the BSD security/authorization system.


ftp
Designated for the file transfer system.


ntp
Designated for the network time system.


audit
Designated for audit messages generated by systems that audit
by means of syslog.


console
Designated for the BSD console system.


cron
Designated for cron/at messages generated by systems that do
logging through syslog. The current versions of cron and at
do not use this facility for logging.


local0-7
Designated for local use.


mark
For timestamp messages produced internally by syslogd.


*
An asterisk indicates all facilities except for the mark
facility.


Recognized values for level are (in descending order of severity):

emerg
For panic conditions that would normally be broadcast to all
users.


alert
For conditions that should be corrected immediately, such as a
corrupted system database.


crit
For warnings about critical conditions, such as hard device
errors.


err
For other errors.


warning
For warning messages.


notice
For conditions that are not error conditions, but may require
special handling. A configuration entry with a level value of
notice must appear on a separate line.


info
Informational messages.


debug
For messages that are normally used only when debugging a
program.


none
Do not send messages from the indicated facility to the
selected file. For example, a selector of

*.debug;mail.none

sends all messages except mail messages to the selected file.


For a given facility and level, syslogd matches all messages for that
level and all higher levels. For example, an entry that specifies a level
of crit also logs messages at the alert and emerg levels.


The action field indicates where to forward the message. Values for this
field can have one of four forms:

o A filename, beginning with a leading slash, which indicates
that messages specified by the selector are to be written to
the specified file. The file is opened in append mode if it
exists. If the file does not exist, logging silently fails for
this action.

o The name of a remote host, prefixed with an @, as with:
@server, which indicates that messages specified by the
selector are to be forwarded to the syslogd on the named host.
The hostname "loghost" is treated, in the default syslog.conf,
as the hostname given to the machine that logs syslogd
messages. Every machine is "loghost" by default, per the hosts
database. It is also possible to specify one machine on a
network to be "loghost" by, literally, naming the machine
"loghost". If the local machine is designated to be "loghost",
then syslogd messages are written to the appropriate files.
Otherwise, they are sent to the machine "loghost" on the
network.

o A comma-separated list of usernames, which indicates that
messages specified by the selector are to be written to the
named users if they are logged in.

o An asterisk, which indicates that messages specified by the
selector are to be written to all logged-in users.


Blank lines are ignored. Lines for which the first nonwhite character is
a '#' are treated as comments.

EXAMPLES


Example 1: A Sample Configuration File




With the following configuration file:


*.notice /var/log/notice
mail.info /var/log/notice
*.crit /var/log/critical
kern,mark.debug /dev/console
kern.err @server
*.emerg *
*.alert root,operator
*.alert;auth.warning /var/log/auth


syslogd(1M) logs all mail system messages except debug messages and all
notice (or higher) messages into a file named /var/log/notice. It logs
all critical messages into /var/log/critical, and all kernel messages and
20-minute marks onto the system console.


Kernel messages of err (error) severity or higher are forwarded to the
machine named server. Emergency messages are forwarded to all users. The
users root and operator are informed of any alert messages. All messages
from the authorization system of warning level or higher are logged in
the file /var/log/auth.


ATTRIBUTES


See attributes(5) for descriptions of the following attributes:


+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Interface Stability | Stable |
+--------------------+-----------------+

SEE ALSO


at(1), crontab(1), logger(1), login(1), lp(1), lpc(1B), lpr(1B), m4(1),
cron(1M), getty(1M), in.ftpd(1M), su(1M), syslogd(1M), syslog(3C),
hosts(4), attributes(5)


November 19, 2013 SYSLOG.CONF(4)