NAME¶
syslog.conf —
configuration file for
syslogd(8)
DESCRIPTION¶
The
syslog.conf file is the configuration file for the
syslogd(8) program. It consists of lines with two fields:
the
selector field which specifies the types of messages and
priorities to which the line applies, and an
action field
which specifies the action to be taken if a message
syslogd
receives matches the selection criteria. The
selector field
is separated from the
action field by one or more tab or
space characters. A rule can be splitted in several lines if all lines except
the last are terminated with a backslash (``´').
The
Selectors function are 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, authpriv, cron, daemon,
kern, lpr, mail, mark, news, syslog, user, uucp and local0 through local7.
These keywords (with the exception of mark) correspond to the similar
“
LOG_
” values specified to the
openlog(3) and
syslog(3) library routines.
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 and debug. These keywords correspond to the similar
(
LOG_
) values specified to the
syslog library routine.
See
syslog(3) for a further descriptions of both the
facility and
level keywords and their
significance.
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.
By default, a
level applies to all messages with the same or
higher
level. The equal (``='') character can be prepended
to a
level to restrict this line of the configuration file
to messages with the very same
level.
An exclamation mark (``!'') prepended to a
level or the
asterisk means that this line of the configuration file does
not apply to the specified level (and higher ones). In
conjunction with the equal sign, you can exclude single
levels as well.
The special
facility ``mark'' receives a message at priority
``info'' every 20 minutes (see
syslogd(8)). This is not
enabled by a
facility field containing an asterisk.
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 five
forms:
- A pathname (beginning with a leading slash). Selected
messages are appended to the file.
You may prepend a minus (``-'') to the path to omit syncing the file after
each message log. This can cause data loss at system crashes, but
increases performance for programs which use logging extensively.
- A named pipe (fifo), beginning with a vertical bar
(``|'') followed by a pathname. The pipe must be created with
mkfifo(8) before syslogd reads its configuration file.
This feature is especially useful fo debugging.
- A hostname (preceded by an at (``@'') sign). Selected
messages are forwarded to the syslogd program on the
named host.
- A comma separated list of users. Selected messages are
written to those users if they are logged in.
- An asterisk. Selected messages are written to all
logged-in users.
Blank lines and lines whose first non-blank character is a hash (``#'')
character are ignored.
EXAMPLES¶
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 *
*.emerg @arpa.berkeley.edu
# 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
FILES¶
- /etc/syslog.conf
- The syslogd(8) configuration file.
BUGS¶
The effects of multiple selectors are sometimes not intuitive. For example
``mail.crit,*.err'' will select ``mail'' facility messages at the level of
``err'' or higher, not at the level of ``crit'' or higher.
SEE ALSO¶
syslog(3),
syslogd(8)