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SYSLOG.CONF(5)		  FreeBSD File Formats Manual		SYSLOG.CONF(5)

NAME
     syslog.conf -- syslogd(8) configuration file

DESCRIPTION
     The syslog.conf file is the configuration file for	the syslogd(8) pro-
     gram.  It consists	of blocks of lines separated by	program	specifica-
     tions, with each line containing 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	characters.

     The Selectors function are	encoded	as a facility, a period	(``.''), an
     optional set of comparison	flags ([<=>]), and a level, with no interven-
     ing 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, ftp,
     kern, lpr,	mail, mark, news, ntp, 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 comparison flags may be used to specify exactly what is logged.  The
     default set of comparison flags are ``=>''	(or, if	you prefer, ``>='' ),
     which means that messages from the	specified facility list	of a priority
     level equal or greater than level will be logged.

     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.  These keywords correspond to the	simi-
     lar ``LOG_'' values specified to the syslog library routine.

     Each block	of lines is separated from the previous	block by a tag.	The
     tag is a line beginning with #!prog or !prog (the former is for compati-
     bility with the previous syslogd, if one is sharing syslog.conf files,
     for example) and each block will be associated with calls to syslog from
     that specific program. A tag for ``foo'' will also	match any message
     logged by the kernel with the prefix ``foo: ''.

     See syslog(3) for a further descriptions of both the facility and level
     keywords and their	significance. It's preferred that selections be	made
     on	facility rather	than program, since the	latter can easily vary in a
     networked environment. In some cases, though, an appropriate facility
     simply doesn't exist.

     If	a received message matches the specified facility and is of the	speci-
     fied level	(or a higher level), and the first word	in the message after
     the date matches the program, 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, how-
     ever, 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 all levels or
     all programs.

     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:

     +o	 A pathname (beginning with a leading slash).  Selected	messages are
	 appended to the file.

     +o	 A hostname (preceded by an at (``@'') sign).  Selected	messages are
	 forwarded to the syslogd program on the named host.

     +o	 A comma separated list	of users.  Selected messages are written to
	 those users if	they are logged	in.

     +o	 An asterisk.  Selected	messages are written to	all logged-in users.

     +o	 A vertical bar	(``|''), followed by a command to pipe the selected
	 messages to.  The command is passed to	a /bin/sh for evaluation, so
	 usual shell metacharacters or input/output redirection	can occur.
	 (Note however that redirecting	stdio(3) buffered output from the
	 invoked command can cause additional delays, or even lost output data
	 in case a logging subprocess exited with a signal.)  The command
	 itself	runs with stdout and stderr redirected to /dev/null.  Upon
	 receipt of a SIGHUP, syslog.conf will close the pipe to the process.
	 If the	process	didn't exit voluntarily, it will be sent a SIGTERM
	 signal	after a	grace period of	up to 60 seconds.

	 The command will only be started once data arrives that should	be
	 piped to it.  If it exited later, it will be restarted	as necessary.
	 So if it is desired that the subprocess should	get exactly one	line
	 of input only (which can be very resource-consuming if	there are a
	 lot of	messages flowing quickly), this	can be achieved	by exiting
	 after just one	line of	input.	If necessary, a	script wrapper can be
	 written to this effect.

	 Unless	the command is a full pipeline,	it's probably useful to	start
	 the command with exec so that the invoking shell process does not
	 wait for the command to complete.  Warning: the process is started
	 under the UID invoking	syslogd(8), normally the superuser.

     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

     # Log daemon messages at debug level only
     daemon.=debug					     /var/log/daemon.debug

     # 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

     # Pipe all	authentication messages	to a filter.
     auth.*				     |exec /usr/local/sbin/authfilter

     # Save ftpd transactions along with mail and news
     !ftpd
     *.*						     /var/log/spoolerr

     # Log kernel firewall reports to a	separate file
     !ipfw
     *.*						     /var/log/ipfw

FILES
     /etc/syslog.conf  syslogd(8) configuration	file

BUGS
     The effects of multiple selectors are sometimes not intuitive.  For exam-
     ple ``mail.crit,*.err'' will select ``mail'' facility messages at the
     level of ``err'' or higher, not at	the level of ``crit'' or higher.

     In	networked environments,	note that not all operating systems implement
     the same set of facilities.  The facilities authpriv, cron, ftp, and ntp
     that are known to this implementation might be absent on the target sys-
     tem.  Even	worse, DEC UNIX	uses facility number 10	(which is authpriv in
     this implementation) to log events	for their AdvFS	file system.

SEE ALSO
     syslog(3),	syslogd(8)

FreeBSD	10.1			 June 9, 1993			  FreeBSD 10.1

NAME | DESCRIPTION | EXAMPLES | FILES | BUGS | SEE ALSO

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