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
36 .Nd log systems messages
39 .Op Fl 468ACcdFkNnosTuv
40 .Op Fl a Ar allowed_peer
41 .Op Fl b Ar bind_address
42 .Op Fl f Ar config_file
43 .Op Fl l Oo Ar mode Ns \&: Oc Ns Ar path
44 .Op Fl m Ar mark_interval
46 .Op Fl p Ar log_socket
47 .Op Fl S Ar logpriv_socket
51 utility reads and logs messages to the system console,
54 machines and/or users as specified by its configuration file.
56 The options are as follows:
57 .Bl -tag -width indent
61 to use IPv4 addresses only.
65 to use IPv6 addresses only.
69 not to interfere with 8-bit data.
72 will replace C1 control characters
73 .Pq ISO 8859 and Unicode characters
77 Note, this option does not change the way
79 alters control characters
80 .Pq see Xr iscntrl 3 .
81 They will always be replaced with their
87 tries to send the message to only one address
88 even if the host has more than one A or AAAA record.
89 If this option is specified,
91 tries to send the message to all addresses.
92 .It Fl a Ar allowed_peer
100 options may be specified.
104 option may be any of the following:
105 .Bl -tag -width "ipaddr[/prefixlen][:service]XX"
117 Accept datagrams from
120 can be specified as an IPv4 address or as an IPv6
121 address enclosed with
127 is the name or number of an UDP service (see
129 the source packet must belong to.
134 accepts UDP packets from any source port.
141 is IPv4 address, a missing
143 will be substituted by the historic class A or class B netmasks if
145 belongs into the address range of class A or B,
153 will be substituted by 128.
156 .Ar domainname Op \&: Ar service
159 Accept datagrams where the reverse address lookup yields
161 for the sender address.
164 is as explained above.
166 can contain special characters of a shell-style pattern such as
172 options are ignored if the
174 option is also specified.
178 .Ar bind_address Op \&: Ar service
187 Bind to a specific address and/or port.
188 The address can be specified as a hostname,
189 and the port as a service name.
190 If an IPv6 address is specified, it should be enclosed with
198 This option can be specified multiple times to bind to
199 multiple addresses and/or ports.
201 Create log files that do not exist
202 .Pq permission is set to Ql Li 0600 .
204 Disable the compression of repeated instances of the same line
205 into a single line of the form
206 .Dq Li "last message repeated N times"
207 when the output is a pipe to another program.
209 disable this compression in all cases.
214 This is probably only of use to developers working on
216 .It Fl f Ar config_file
217 Specify the pathname of an alternate configuration file;
219 .Pa /etc/syslog.conf .
224 rather than going into daemon mode.
225 This is useful if some other process uses
231 and wants to monitor when and how it exits.
233 Disable the translation of
234 messages received with facility
240 facility is reserved for messages read directly from
242 .It Fl m Ar mark_interval
243 Select the number of minutes between
246 the default is 20 minutes.
248 Disable binding on UDP sockets.
249 RFC 3164 recommends that outgoing
251 messages should originate from the privileged port,
254 the recommended behavior.
258 Disable DNS query for every request.
260 Prefix kernel messages with the full kernel boot file as determined by
262 Without this, the kernel message prefix is always
264 .It Fl p Ar log_socket
265 Specify the pathname of an alternate log socket to be used instead;
271 the default pathname is replaced with the specified one.
274 options are specified,
275 the remaining pathnames are treated as additional log sockets.
277 Specify an alternative file in which to store the process ID.
279 .Pa /var/run/syslog.pid .
280 .It Fl S Ar logpriv_socket
281 Specify the pathname of an alternate log socket for privileged
282 applications to be used instead;
284 .Pa /var/run/logpriv .
288 the default pathname is replaced with the specified one.
291 options are specified,
292 the remaining pathnames are treated as additional log sockets.
293 .It Fl l Oo Ar mode Ns \&: Oc Ns Ar path
294 Specify a location where
296 should place an additional log socket.
297 The primary use for this is to place additional log sockets in
299 of various chroot filespaces.
300 File permissions for socket can be specified in octal representation in
302 delimited with a colon.
303 The socket location must be specified as an absolute pathname in
306 Operate in secure mode.
307 Do not log messages from remote machines.
309 no network socket will be opened at all,
310 which also disables logging to remote machines.
312 Always use the local time and date for messages received from the network,
313 instead of the timestamp field supplied in the message by the remote host.
314 This is useful if some of the originating hosts cannot keep time properly
315 or are unable to generate a correct timestamp.
317 Unique priority logging.
318 Only log messages at the specified priority.
320 messages at the stated priority or higher are logged.
321 This option changes the default comparison from
328 the numeric facility and priority are
329 logged with each locally-written message.
330 If specified more than once,
331 the names of the facility and priority are logged with each locally-written
337 utility reads its configuration file when it starts up and whenever it
338 receives a hangup signal.
339 For information on the format of the configuration file,
345 utility reads messages from the
350 .Pa /var/run/logpriv ,
351 from an Internet domain socket specified in
353 and from the special device
355 .Pq to read kernel messages .
359 utility creates its process ID file,
361 .Pa /var/run/syslog.pid ,
362 and stores its process
364 This can be used to kill or reconfigure
369 should consist of a single line.
370 The message can contain a priority code,
371 which should be a preceding
372 decimal number in angle braces,
375 This priority code should map into the priorities defined in the
379 For security reasons,
381 will not append to log files that do not exist
385 therefore, they must be created manually before running
388 The date and time are taken from the received message.
389 If the format of the timestamp field is incorrect,
390 time obtained from the local host is used instead.
391 This can be overridden by the
395 .Bl -tag -width /var/run/syslog.pid -compact
396 .It Pa /etc/syslog.conf
398 .It Pa /var/run/syslog.pid
399 default process ID file
403 domain datagram log socket
404 .It Pa /var/run/logpriv
406 socket for privileged applications
432 The ability to log messages received in UDP packets is equivalent to
433 an unauthenticated remote disk-filling service,
434 and should probably be disabled by default.
436 .No inter- Ns Nm syslogd
437 authentication mechanism ought to be worked out.
438 To prevent the worst abuse,
441 option is therefore highly recommended.
445 matching algorithm does not pretend to be very efficient;
446 use of numeric IP addresses is faster than domain name comparison.
447 Since the allowed peer list is being walked linearly,
448 peer groups where frequent messages are being anticipated
449 from should be put early into the
453 The log socket was moved from
455 to ease the use of a read-only root file system.
457 some old binaries so that a symbolic link might be used for a