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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 : Oc Ns Ar path
44 .Op Fl m Ar mark_interval
46 .Op Fl p Ar log_socket
50 utility reads and logs messages to the system console, log files, other
51 machines and/or users as specified by its configuration file.
53 The options are as follows:
54 .Bl -tag -width indent
58 to use IPv4 addresses only.
62 to use IPv6 addresses only.
66 not to interfere with 8-bit data. Normally
68 will replace C1 control characters
69 .Pq ISO 8859 and Unicode characters
73 Note, this option does not change the way
75 alters control characters
76 .Pq see Xr iscntrl 3 .
77 They will always be replaced with their
83 tries to send the message to only one address
84 even if the host has more than one A or AAAA record.
85 If this option is specified,
87 tries to send the message to all addresses.
88 .It Fl a Ar allowed_peer
96 options may be specified.
100 option may be any of the following:
101 .Bl -tag -width "ipaddr/masklen[:service]XX"
109 Accept datagrams from
111 (in the usual dotted quad notation) with
113 bits being taken into account when doing the address comparison.
115 can be also IPv6 address by enclosing the address with
121 is the name or number of an UDP service (see
123 the source packet must belong to.
128 allows packets being sent from any UDP port.
135 is IPv4 address, a missing
137 will be substituted by the historic class A or class B netmasks if
139 belongs into the address range of class A or B, respectively, or
143 is IPv6 address, a missing
145 will be substituted by 128.
148 .Ar domainname Op : Ar service
151 Accept datagrams where the reverse address lookup yields
153 for the sender address.
156 is as explained above.
159 .No * Ar domainname Op : Ar service
162 Same as before, except that any source host whose name
171 options are ignored if the
173 option is also specified.
177 .Ar bind_address Op : Ar service
186 Bind to a specific address and/or port.
187 The address can be specified as a hostname,
188 and the port as a service name.
189 If an IPv6 address is specified, it should be enclosed with
198 Create log files that do not exist (permission is set to
201 Disable the compression of repeated instances of the same line
202 into a single line of the form
203 .Dq Li "last message repeated N times"
204 when the output is a pipe to another program.
205 If specified twice, disable this compression in all cases.
210 This is probably only of use to developers working on
213 Specify the pathname of an alternate configuration file;
215 .Pa /etc/syslog.conf .
219 in the foreground, rather than going into daemon mode. This is useful if
220 some other process uses
226 and wants to monitor when and how it exits.
228 Disable the translation of
229 messages received with facility
235 facility is reserved for messages read directly from
238 Select the number of minutes between
240 messages; the default is 20 minutes.
242 Disable binding on UDP sockets. RFC 3164 recommends that outgoing
243 syslogd messages should originate from the privileged port, this
246 the recommended behavior. This option inherits
249 Disable dns query for every request.
251 Prefix kernel messages with the full kernel boot file as determined by
253 Without this, the kernel message prefix is always
256 Specify the pathname of an alternate log socket to be used instead;
260 Specify an alternative file in which to store the process ID.
262 .Pa /var/run/syslog.pid .
264 Specify the pathname of an alternate log socket for privileged
265 applications to be used instead; the default is
266 .Pa /var/run/logpriv .
268 Specify a location where
270 should place an additional log socket.
271 The primary use for this is to place additional log sockets in
273 of various chroot filespaces.
274 File permissions for socket can be specified in octal representation
275 before socket name, delimited with a colon.
276 Path to socket location must be absolute.
278 Operate in secure mode.
279 Do not log messages from remote machines.
281 specified twice, no network socket will be opened at all, which also
282 disables logging to remote machines.
284 Always use the local time and date for messages received from the network,
285 instead of the timestamp field supplied in the message by the remote host.
286 This is useful if some of the originating hosts can't keep time properly
287 or are unable to generate a correct timestamp.
289 Unique priority logging.
290 Only log messages at the specified priority.
291 Without this option, messages at the stated priority or higher are logged.
292 This option changes the default comparison from
298 If specified once, the numeric facility and priority are
299 logged with each locally-written message.
300 If specified more than once,
301 the names of the facility and priority are logged with each locally-written
307 utility reads its configuration file when it starts up and whenever it
308 receives a hangup signal.
309 For information on the format of the configuration file,
315 utility reads messages from the
320 .Pa /var/run/logpriv ,
321 from an Internet domain socket specified in
323 and from the special device
325 (to read kernel messages).
329 utility creates its process ID file,
331 .Pa /var/run/syslog.pid ,
332 and stores its process
334 This can be used to kill or reconfigure
339 should consist of a single line.
340 The message can contain a priority code, which should be a preceding
341 decimal number in angle braces, for example,
343 This priority code should map into the priorities defined in the
347 For security reasons,
349 will not append to log files that do not exist (unless
351 option is specified);
352 therefore, they must be created manually before running
355 The date and time are taken from the received message.
356 If the format of the timestamp field is incorrect,
357 time obtained from the local host is used instead.
358 This can be overridden by the
362 .Bl -tag -width /var/run/syslog.pid -compact
363 .It Pa /etc/syslog.conf
365 .It Pa /var/run/syslog.pid
366 default process ID file
370 domain datagram log socket
371 .It Pa /var/run/logpriv
373 socket for privileged applications
399 The ability to log messages received in UDP packets is equivalent to
400 an unauthenticated remote disk-filling service, and should probably be
403 .No inter- Ns Nm syslogd
404 authentication mechanism ought to be worked out.
408 option is therefore highly recommended.
412 matching algorithm does not pretend to be very efficient; use of numeric
413 IP addresses is faster than domain name comparison.
415 peer list is being walked linearly, peer groups where frequent messages
416 are being anticipated from should be put early into the
420 The log socket was moved from
422 to ease the use of a read-only root file system.
424 some old binaries so that a symbolic link might be used for a