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

     syslog.conf -- syslogd(8) configuration file

     The syslog.conf file is the configuration file for	the syslogd(8) pro-
     gram.  It consists	of blocks of lines separated by	program	and hostname
     specifications, 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(8)	receives matches the selection criteria.  The selector
     field is separated	from the action	field by one or	more tab characters or

     Note that if you use spaces as separators,	your syslog.conf might be in-
     compatible	with other Unices or Unix-like systems.	 This functionality
     was added for the ease of configuration (e.g. it is possible to cut-and-
     paste into	syslog.conf), and to avoid possible mistakes.  This change
     however preserves backwards compatibility with the	old style of the
     syslog.conf (i.e. tab characters only).

     The selectors are encoded as a facility, a	period ("."), an optional set
     of	comparison flags ([<=>]), 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, console,	cron, daemon,
     ftp, kern,	lpr, mail, mark, news, ntp, security, syslog, user, uucp and
     local0 through local7.  These keywords (with the exception	of mark) cor-
     respond 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(3) library routine.

     Each block	of lines is separated from the previous	block by a program or
     hostname specification.  A	block will only	log messages corresponding to
     the most recent program and hostname specifications given.	 Thus, a block
     which selects `ppp' as the	program, directly followed by a	block that se-
     lects messages from the hostname `dialhost', then the second block	will
     only log messages from the	ppp(8) program on dialhost.

     A program specification is	a line beginning with `#!prog' or `!prog' (the
     former is for compatibility with the previous syslogd, if one is sharing
     syslog.conf files,	for example) and the following blocks will be associ-
     ated with calls to	syslog(3) from that specific program.  A program spec-
     ification for `foo' will also match any message logged by the kernel with
     the prefix	`foo: '.  A hostname specification of the form `#+hostname' or
     `+hostname' and the following blocks will be applied to messages received
     from the specified	hostname.  Alternatively, a hostname specification
     `#-hostname' or `-hostname' causes	the following blocks to	be applied to
     messages from any host but	the one	specified.  If the hostname is given
     as	`@', the local hostname	will be	used.  A program or hostname specifi-
     cation may	be reset by giving the program or hostname as `*'.

     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, 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 all levels	or all

     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(8) 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 mes-
	 sages to.  The	command	is passed to sh(1) 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, syslogd(8) will close the pipe	to the process.	 If the
	 process didn't	exit voluntarily, it will be sent a SIGTERM signal af-
	 ter 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 af-
	 ter 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.

     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						     *

     # 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
     *.*						     /var/log/spoolerr

     # Log all security	messages to a separate file.
     security.*						     /var/log/security

     # Log all writes to /dev/console to a separate file.
     console.*						     /var/log/console.log

     The "kern"	facility is usually reserved for messages generated by the lo-
     cal kernel.  Other	messages logged	with facility "kern" are usually
     translated	to facility "user".  This translation can be disabled, see
     syslogd(8)	for details.

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

     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.

     syslog(3),	syslogd(8)

BSD				 June 9, 1993				   BSD


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