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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
197 This option can be specified multiple times to bind to
198 multiple addresses and/or ports.
200 Create log files that do not exist (permission is set to
203 Disable the compression of repeated instances of the same line
204 into a single line of the form
205 .Dq Li "last message repeated N times"
206 when the output is a pipe to another program.
207 If specified twice, disable this compression in all cases.
212 This is probably only of use to developers working on
215 Specify the pathname of an alternate configuration file;
217 .Pa /etc/syslog.conf .
221 in the foreground, rather than going into daemon mode. This is useful if
222 some other process uses
228 and wants to monitor when and how it exits.
230 Disable the translation of
231 messages received with facility
237 facility is reserved for messages read directly from
240 Select the number of minutes between
242 messages; the default is 20 minutes.
244 Disable binding on UDP sockets. RFC 3164 recommends that outgoing
245 syslogd messages should originate from the privileged port, this
248 the recommended behavior. This option inherits
251 Disable dns query for every request.
253 Prefix kernel messages with the full kernel boot file as determined by
255 Without this, the kernel message prefix is always
258 Specify the pathname of an alternate log socket to be used instead;
262 Specify an alternative file in which to store the process ID.
264 .Pa /var/run/syslog.pid .
266 Specify the pathname of an alternate log socket for privileged
267 applications to be used instead; the default is
268 .Pa /var/run/logpriv .
270 Specify a location where
272 should place an additional log socket.
273 The primary use for this is to place additional log sockets in
275 of various chroot filespaces.
276 File permissions for socket can be specified in octal representation
277 before socket name, delimited with a colon.
278 Path to socket location must be absolute.
280 Operate in secure mode.
281 Do not log messages from remote machines.
283 specified twice, no network socket will be opened at all, which also
284 disables logging to remote machines.
286 Always use the local time and date for messages received from the network,
287 instead of the timestamp field supplied in the message by the remote host.
288 This is useful if some of the originating hosts can't keep time properly
289 or are unable to generate a correct timestamp.
291 Unique priority logging.
292 Only log messages at the specified priority.
293 Without this option, messages at the stated priority or higher are logged.
294 This option changes the default comparison from
300 If specified once, the numeric facility and priority are
301 logged with each locally-written message.
302 If specified more than once,
303 the names of the facility and priority are logged with each locally-written
309 utility reads its configuration file when it starts up and whenever it
310 receives a hangup signal.
311 For information on the format of the configuration file,
317 utility reads messages from the
322 .Pa /var/run/logpriv ,
323 from an Internet domain socket specified in
325 and from the special device
327 (to read kernel messages).
331 utility creates its process ID file,
333 .Pa /var/run/syslog.pid ,
334 and stores its process
336 This can be used to kill or reconfigure
341 should consist of a single line.
342 The message can contain a priority code, which should be a preceding
343 decimal number in angle braces, for example,
345 This priority code should map into the priorities defined in the
349 For security reasons,
351 will not append to log files that do not exist (unless
353 option is specified);
354 therefore, they must be created manually before running
357 The date and time are taken from the received message.
358 If the format of the timestamp field is incorrect,
359 time obtained from the local host is used instead.
360 This can be overridden by the
364 .Bl -tag -width /var/run/syslog.pid -compact
365 .It Pa /etc/syslog.conf
367 .It Pa /var/run/syslog.pid
368 default process ID file
372 domain datagram log socket
373 .It Pa /var/run/logpriv
375 socket for privileged applications
401 The ability to log messages received in UDP packets is equivalent to
402 an unauthenticated remote disk-filling service, and should probably be
405 .No inter- Ns Nm syslogd
406 authentication mechanism ought to be worked out.
410 option is therefore highly recommended.
414 matching algorithm does not pretend to be very efficient; use of numeric
415 IP addresses is faster than domain name comparison.
417 peer list is being walked linearly, peer groups where frequent messages
418 are being anticipated from should be put early into the
422 The log socket was moved from
424 to ease the use of a read-only root file system.
426 some old binaries so that a symbolic link might be used for a