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28 .\" @(#)syslogd.8 8.1 (Berkeley) 6/6/93
36 .Nd log systems messages
39 .Op Fl 468ACcdkNnosTuv
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.
174 .It Fl b Ar bind_address
175 Specify one specific IP address or hostname to bind to.
176 If a hostname is specified,
177 the IPv4 or IPv6 address which corresponds to it is used.
179 Create log files that do not exist (permission is set to
182 Disable the compression of repeated instances of the same line
183 into a single line of the form
184 .Dq Li "last message repeated N times"
185 when the output is a pipe to another program.
186 If specified twice, disable this compression in all cases.
191 This is probably only of use to developers working on
194 Specify the pathname of an alternate configuration file;
196 .Pa /etc/syslog.conf .
198 Disable the translation of
199 messages received with facility
205 facility is reserved for messages read directly from
208 Select the number of minutes between
210 messages; the default is 20 minutes.
212 Disable binding on UDP sockets. RFC 3164 recommends that outgoing
213 syslogd messages should originate from the privileged port, this
216 the recommended behavior. This option inherits
219 Disable dns query for every request.
221 Prefix kernel messages with the full kernel boot file as determined by
223 Without this, the kernel message prefix is always
226 Specify the pathname of an alternate log socket to be used instead;
230 Specify an alternative file in which to store the process ID.
232 .Pa /var/run/syslog.pid .
234 Specify the pathname of an alternate log socket for privileged
235 applications to be used instead; the default is
236 .Pa /var/run/logpriv .
238 Specify a location where
240 should place an additional log socket.
241 The primary use for this is to place additional log sockets in
243 of various chroot filespaces.
244 File permissions for socket can be specified in octal representation
245 before socket name, delimited with a colon.
246 Path to socket location must be absolute.
248 Operate in secure mode.
249 Do not log messages from remote machines.
251 specified twice, no network socket will be opened at all, which also
252 disables logging to remote machines.
254 Always use the local time and date for messages received from the network,
255 instead of the timestamp field supplied in the message by the remote host.
256 This is useful if some of the originating hosts can't keep time properly
257 or are unable to generate a correct timestamp.
259 Unique priority logging.
260 Only log messages at the specified priority.
261 Without this option, messages at the stated priority or higher are logged.
262 This option changes the default comparison from
268 If specified once, the numeric facility and priority are
269 logged with each locally-written message.
270 If specified more than once,
271 the names of the facility and priority are logged with each locally-written
277 utility reads its configuration file when it starts up and whenever it
278 receives a hangup signal.
279 For information on the format of the configuration file,
285 utility reads messages from the
290 .Pa /var/run/logpriv ,
291 from an Internet domain socket specified in
293 and from the special device
295 (to read kernel messages).
299 utility creates its process ID file,
301 .Pa /var/run/syslog.pid ,
302 and stores its process
304 This can be used to kill or reconfigure
309 should consist of a single line.
310 The message can contain a priority code, which should be a preceding
311 decimal number in angle braces, for example,
313 This priority code should map into the priorities defined in the
317 For security reasons,
319 will not append to log files that do not exist (unless
321 option is specified);
322 therefore, they must be created manually before running
325 The date and time are taken from the received message.
326 If the format of the timestamp field is incorrect,
327 time obtained from the local host is used instead.
328 This can be overriden by the
332 .Bl -tag -width /var/run/syslog.pid -compact
333 .It Pa /etc/syslog.conf
335 .It Pa /var/run/syslog.pid
336 default process ID file
340 domain datagram log socket
341 .It Pa /var/run/logpriv
343 socket for privileged applications
369 The ability to log messages received in UDP packets is equivalent to
370 an unauthenticated remote disk-filling service, and should probably be
373 .No inter- Ns Nm syslogd
374 authentication mechanism ought to be worked out.
378 option is therefore highly recommended.
382 matching algorithm does not pretend to be very efficient; use of numeric
383 IP addresses is faster than domain name comparison.
385 peer list is being walked linearly, peer groups where frequent messages
386 are being anticipated from should be put early into the
390 The log socket was moved from
392 to ease the use of a read-only root file system.
394 some old binaries so that a symbolic link might be used for a