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32 .\" @(#)syslog.conf.5 8.1 (Berkeley) 6/9/93
33 .\" $FreeBSD: src/usr.sbin/syslogd/syslog.conf.5,v 1.16.2.11 2003/03/12 22:08:15 trhodes Exp $
46 file is the configuration file for the
50 blocks of lines separated by
54 specifications (separations appear along on the line),
55 with each line containing two fields: the
57 field which specifies the types of messages and priorities to which the
60 field which specifies the action to be taken if a message
62 receives matches the selection criteria.
65 field is separated from the
67 field by one or more tab characters or spaces.
69 Note that if you use spaces as separators, your
71 might be incompatible with other Unices or Unix-like systems.
72 This functionality was added for ease of configuration
73 (e.g. it is possible to cut-and-paste into
75 and to avoid possible mistakes.
76 This change however preserves
77 backwards compatibility with the old style of
79 (i.e. tab characters only).
87 an optional set of comparison flags
88 .Pq Oo \&! Oc Op <=> ,
91 with no intervening white-space.
100 describes the part of the system generating the message, and is one of
101 the following keywords: auth, authpriv, console, cron, daemon, ftp, kern,
102 lpr, mail, mark, news, ntp, security, syslog, user, uucp and local0 through
104 These keywords (with the exception of mark) correspond to
107 values specified to the
115 may be used to specify exactly what is logged.
116 The default comparison is
120 which means that messages from the specified
122 list, and of a priority
123 level equal to or greater than
126 Comparison flags beginning with
128 will have their logical sense inverted.
131 means all levels except info and
133 has the same meaning as
138 describes the severity of the message, and is a keyword from the
139 following ordered list (higher to lower): emerg, alert, crit, err,
140 warning, notice, info and debug.
141 These keywords correspond to
144 values specified to the
148 Each block of lines is separated from the previous block by a
153 A block will only log messages corresponding to the most recent
157 specifications given.
158 Thus, with a block which selects
162 directly followed by a block that selects messages from the
165 the second block will only log messages
172 specification is a line beginning with
176 (the former is for compatibility with the previous syslogd, if one is sharing
179 and the following blocks will be associated with calls to
181 from that specific program.
186 will also match any message logged by the kernel with the prefix
192 specification works just like the previous one,
197 specification will match any message but the ones from that
201 specification of the form
205 means the following blocks will be applied to messages
206 received from the specified hostname.
213 causes the following blocks to be applied to messages
214 from any host but the one specified.
215 If the hostname is given as
217 the local hostname will be used.
222 specification may be reset by giving the program or hostname as
227 for further descriptions of both the
231 keywords and their significance.
232 It's preferred that selections be made on
236 since the latter can easily vary in a networked environment.
238 though, an appropriate
240 simply doesn't exist.
242 If a received message matches the specified
244 and is of the specified
246 .Em (or a higher level) ,
247 and the first word in the message after the date matches the
249 the action specified in the
255 may be specified for a single
257 by separating them with semicolon
260 It is important to note, however, that each
262 can modify the ones preceding it.
266 may be specified for a single
268 by separating them with comma
274 can be used to specify all
284 receives a message at priority
289 This is not enabled by a
291 field containing an asterisk.
296 disables a particular
301 field of each line specifies the action to be taken when the
303 field selects a message.
304 There are five forms:
307 A pathname (beginning with a leading slash).
308 Selected messages are appended to the file.
310 A hostname (preceded by an at
313 Selected messages are forwarded to the
315 program on the named host.
317 A comma separated list of users.
318 Selected messages are written to those users
319 if they are logged in.
322 Selected messages are written to all logged-in users.
326 followed by a command to pipe the selected
327 messages to. The command is passed to
329 for evaluation, so usual shell metacharacters or input/output
330 redirection can occur. (Note however that redirecting
332 buffered output from the invoked command can cause additional delays,
333 or even lost output data in case a logging subprocess exited with a
334 signal.) The command itself runs with
343 will close the pipe to the process. If the process didn't exit
344 voluntarily, it will be sent a
346 signal after a grace period of up to 60 seconds.
348 The command will only be started once data arrives that should be piped
349 to it. If it exited later, it will be restarted as necessary. So if it
350 is desired that the subprocess should get exactly one line of input only
351 (which can be very resource-consuming if there are a lot of messages
352 flowing quickly), this can be achieved by exiting after just one line of
353 input. If necessary, a script wrapper can be written to this effect.
355 Unless the command is a full pipeline, it's probably useful to
356 start the command with
358 so that the invoking shell process does not wait for the command to
359 complete. Warning: the process is started under the UID invoking
361 normally the superuser.
364 Blank lines and lines whose first non-blank character is a hash
366 character are ignored.
368 A configuration file might appear as follows:
370 # Log all kernel messages, authentication messages of
371 # level notice or higher, and anything of level err or
372 # higher to the console.
373 # Don't log private authentication messages!
374 *.err;kern.*;auth.notice;authpriv.none /dev/console
376 # Log anything (except mail) of level info or higher.
377 # Don't log private authentication messages!
378 *.info;mail.none;authpriv.none /var/log/messages
380 # Log daemon messages at debug level only
381 daemon.=debug /var/log/daemon.debug
383 # The authpriv file has restricted access.
384 authpriv.* /var/log/secure
386 # Log all the mail messages in one place.
387 mail.* /var/log/maillog
389 # Everybody gets emergency messages, plus log them on another
392 *.emerg @arpa.berkeley.edu
394 # Root and Eric get alert and higher messages.
397 # Save mail and news errors of level err and higher in a
399 uucp,news.crit /var/log/spoolerr
401 # Pipe all authentication messages to a filter.
402 auth.* |exec /usr/local/sbin/authfilter
404 # Save ftpd transactions along with mail and news
406 *.* /var/log/spoolerr
408 # Log all security messages to a separate file.
409 security.* /var/log/security
411 # Log all writes to /dev/console to a separate file.
412 console.* /var/log/console.log
414 .Sh IMPLEMENTATION NOTES
417 facility is usually reserved for messages
418 generated by the local kernel.
419 Other messages logged with facility
421 are usually translated to facility
423 This translation can be disabled;
428 .Bl -tag -width /etc/syslog.conf -compact
429 .It Pa /etc/syslog.conf
434 The effects of multiple
436 are sometimes not intuitive.
441 facility messages at the level of
443 or higher, not at the level of
447 In networked environments, note that not all operating systems
448 implement the same set of facilities. The facilities
449 authpriv, cron, ftp, and ntp that are known to this implementation
450 might be absent on the target system. Even worse, DEC UNIX uses
451 facility number 10 (which is authpriv in this implementation) to
452 log events for their AdvFS file system.