1 .\" Copyright (c) 1983, 1986, 1991, 1993
2 .\" The Regents of the University of California. All rights reserved.
4 .\" Redistribution and use in source and binary forms, with or without
5 .\" modification, are permitted provided that the following conditions
7 .\" 1. Redistributions of source code must retain the above copyright
8 .\" notice, this list of conditions and the following disclaimer.
9 .\" 2. Redistributions in binary form must reproduce the above copyright
10 .\" notice, this list of conditions and the following disclaimer in the
11 .\" documentation and/or other materials provided with the distribution.
12 .\" 3. Neither the name of the University nor the names of its contributors
13 .\" may be used to endorse or promote products derived from this software
14 .\" without specific prior written permission.
16 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
17 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
20 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 .\" @(#)syslogd.8 8.1 (Berkeley) 6/6/93
35 .Nd log systems messages
38 .Op Fl 468ACcdFHkNnosTuv
39 .Op Fl a Ar allowed_peer
40 .Op Fl b Ar bind_address
41 .Op Fl f Ar config_file
42 .Op Fl l Oo Ar mode Ns \&: Oc Ns Ar path
43 .Op Fl M Ar fwd_length
44 .Op Fl m Ar mark_interval
47 .Op Fl p Ar log_socket
48 .Op Fl S Ar logpriv_socket
52 utility reads and logs messages to the system console,
55 machines and/or users as specified by its configuration file.
57 The options are as follows:
58 .Bl -tag -width indent
62 to use IPv4 addresses only.
66 to use IPv6 addresses only.
70 not to interfere with 8-bit data.
73 will replace C1 control characters
74 .Pq ISO 8859 and Unicode characters
78 Note, this option does not change the way
80 alters control characters
81 .Pq see Xr iscntrl 3 .
82 They will always be replaced with their
88 tries to send the message to only one address
89 even if the host has more than one A or AAAA record.
90 If this option is specified,
92 tries to send the message to all addresses.
93 .It Fl a Ar allowed_peer
101 options may be specified.
105 option may be any of the following:
106 .Bl -tag -width "ipaddr[/prefixlen][:service]XX"
118 Accept datagrams from
121 can be specified as an IPv4 address or as an IPv6
122 address enclosed with
128 is the name or number of an UDP service (see
130 the source packet must belong to.
135 accepts UDP packets from any source port.
142 is IPv4 address, a missing
144 will be substituted by the historic class A or class B netmasks if
146 belongs into the address range of class A or B,
154 will be substituted by 128.
157 .Ar domainname Op \&: Ar service
160 Accept datagrams where the reverse address lookup yields
162 for the sender address.
165 is as explained above.
167 can contain special characters of a shell-style pattern such as
173 options are ignored if the
175 option is also specified.
179 .Ar bind_address Op \&: Ar service
188 Bind to a specific address and/or port.
189 The address can be specified as a hostname,
190 and the port as a service name.
191 If an IPv6 address is specified, it should be enclosed with
199 This option can be specified multiple times to bind to
200 multiple addresses and/or ports.
202 Create log files that do not exist
203 .Pq permission is set to Ql Li 0600 .
205 Disable the compression of repeated instances of the same line
206 into a single line of the form
207 .Dq Li "last message repeated N times"
208 when the output is a pipe to another program.
210 disable this compression in all cases.
215 This is probably only of use to developers working on
217 .It Fl f Ar config_file
218 Specify the pathname of an alternate configuration file;
220 .Pa /etc/syslog.conf .
225 rather than going into daemon mode.
226 This is useful if some other process uses
232 and wants to monitor when and how it exits.
234 When logging remote messages use hostname from the message (if supplied)
235 instead of using address from which the message was received.
237 Disable the translation of
238 messages received with facility
244 facility is reserved for messages read directly from
246 .It Fl M Ar fwd_length
247 Set the limit on the length of forwarded messages.
248 The minimum is 480 octets.
249 The maximum for RFC 3164 output format is 1024 octets.
250 The default is 1024 octets.
251 .It Fl m Ar mark_interval
252 Select the number of minutes between
255 the default is 20 minutes.
257 Disable binding on UDP sockets.
258 RFC 3164 recommends that outgoing
260 messages should originate from the privileged port,
263 the recommended behavior.
267 Disable DNS query for every request.
269 Select the output format of generated log messages.
274 are used to generate RFC 3164 log messages.
279 are used to generate RFC 5424 log messages,
280 having RFC 3339 timestamps with microsecond precision.
281 The default is to generate RFC 3164 log messages.
283 Prefix kernel messages with the full kernel boot file as determined by
285 Without this, the kernel message prefix is always
287 .It Fl p Ar log_socket
288 Specify the pathname of an alternate log socket to be used instead;
294 the default pathname is replaced with the specified one.
297 options are specified,
298 the remaining pathnames are treated as additional log sockets.
300 Specify an alternative file in which to store the process ID.
302 .Pa /var/run/syslog.pid .
303 .It Fl S Ar logpriv_socket
304 Specify the pathname of an alternate log socket for privileged
305 applications to be used instead;
307 .Pa /var/run/logpriv .
311 the default pathname is replaced with the specified one.
314 options are specified,
315 the remaining pathnames are treated as additional log sockets.
316 .It Fl l Oo Ar mode Ns \&: Oc Ns Ar path
317 Specify a location where
319 should place an additional log socket.
320 The primary use for this is to place additional log sockets in
322 of various chroot filespaces.
323 File permissions for socket can be specified in octal representation in
325 delimited with a colon.
326 The socket location must be specified as an absolute pathname in
329 Operate in secure mode.
330 Do not log messages from remote machines.
332 no network socket will be opened at all,
333 which also disables logging to remote machines.
335 Always use the local time and date for messages received from the network,
336 instead of the timestamp field supplied in the message by the remote host.
337 This is useful if some of the originating hosts cannot keep time properly
338 or are unable to generate a correct timestamp.
340 Unique priority logging.
341 Only log messages at the specified priority.
343 messages at the stated priority or higher are logged.
344 This option changes the default comparison from
351 the numeric facility and priority are
352 logged with each locally-written message.
353 If specified more than once,
354 the names of the facility and priority are logged with each locally-written
357 This option only affects the formatting of RFC 3164 messages.
358 Messages formatted according to RFC 5424 always include a
359 facility/priority number.
364 utility reads its configuration file when it starts up and whenever it
365 receives a hangup signal.
366 For information on the format of the configuration file,
372 utility reads messages from the
377 .Pa /var/run/logpriv ,
378 from an Internet domain socket specified in
380 and from the special device
382 .Pq to read kernel messages .
386 utility creates its process ID file,
388 .Pa /var/run/syslog.pid ,
389 and stores its process
391 This can be used to kill or reconfigure
396 should consist of a single line.
397 The message can contain a priority code,
398 which should be a preceding
399 decimal number in angle braces,
402 This priority code should map into the priorities defined in the
406 For security reasons,
408 will not append to log files that do not exist
412 therefore, they must be created manually before running
415 The date and time are taken from the received message.
416 If the format of the timestamp field is incorrect,
417 time obtained from the local host is used instead.
418 This can be overridden by the
422 .Bl -tag -width /var/run/syslog.pid -compact
423 .It Pa /etc/syslog.conf
425 .It Pa /var/run/syslog.pid
426 default process ID file
430 domain datagram log socket
431 .It Pa /var/run/logpriv
433 socket for privileged applications
459 The ability to log messages received in UDP packets is equivalent to
460 an unauthenticated remote disk-filling service,
461 and should probably be disabled by default.
463 .No inter- Ns Nm syslogd
464 authentication mechanism ought to be worked out.
465 To prevent the worst abuse,
468 option is therefore highly recommended.
472 matching algorithm does not pretend to be very efficient;
473 use of numeric IP addresses is faster than domain name comparison.
474 Since the allowed peer list is being walked linearly,
475 peer groups where frequent messages are being anticipated
476 from should be put early into the
480 The log socket was moved from
482 to ease the use of a read-only root file system.
484 some old binaries so that a symbolic link might be used for a