xref: /netbsd-src/usr.sbin/syslogd/syslogd.8 (revision fad4c9f71477ae11cea2ee75ec82151ac770a534)
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30.\"     from: @(#)syslogd.8	8.1 (Berkeley) 6/6/93
31.\"
32.Dd April 19, 2006
33.Dt SYSLOGD 8
34.Os
35.Sh NAME
36.Nm syslogd
37.Nd log systems messages
38.Sh SYNOPSIS
39.Nm
40.Op Fl dnrSsTUv
41.Bk -words
42.Op Fl f Ar config_file
43.Ek
44.Bk -words
45.Op Fl g Ar group
46.Ek
47.Bk -words
48.Op Fl m Ar mark_interval
49.Ek
50.Bk -words
51.Op Fl P Ar file_list
52.Ek
53.Bk -words
54.Oo
55.Fl p Ar log_socket
56.Op Fl p Ar log_socket2 ...
57.Oc
58.Ek
59.Bk -words
60.Op Fl t Ar chroot_dir
61.Ek
62.Bk -words
63.Op Fl u Ar user
64.Ek
65.Sh DESCRIPTION
66.Nm
67reads and logs messages to the system console, log files, other
68machines and/or users as specified by its configuration file.
69The options are as follows:
70.Bl -tag -width 15n
71.It Fl d
72Enable debugging to the standard output,
73and do not disassociate from the controlling terminal.
74.It Fl f
75Specify the pathname of an alternative configuration file;
76the default is
77.Pa /etc/syslog.conf .
78.It Fl g Ar group
79Set GID to
80.Ar group
81after the sockets and log files have been opened.
82.It Fl m
83Select the number of minutes between ``mark'' messages;
84the default is 20 minutes.
85.It Fl n
86Do not perform hostname lookups; report only numeric addresses.
87.It Fl P
88Specify the pathname of a file containing a list of sockets to be
89created.
90The format of the file is simply one socket per line.
91.It Fl p
92Specify the pathname of a log socket.
93Multiple
94.Fl p
95options create multiple log sockets.
96If no
97.Fl p
98arguments are created, the default socket of
99.Pa /var/run/log
100is used.
101.It Fl r
102Disable the compression of repeated instances of the same line
103into a single line of the form
104.Dq last message repeated N times .
105.It Fl S
106Sync kernel messages to disk immediately.
107.It Fl s
108Select
109.Dq secure
110mode, in which
111.Nm
112does not listen on a UDP socket but only communicates over a
113.Ux
114domain socket.
115This is valuable when the machine on
116which
117.Nm
118runs is subject to attack over the network and it is desired
119that the machine be protected from attempts to remotely fill logs
120and similar attacks.
121.It Fl t Ar chroot_dir
122.Xr chroot 2
123to
124.Ar chroot_dir
125after the sockets and log files have been opened.
126.It Fl T
127Always use the local time and date for messages received from the
128network, instead of the timestamp field supplied in the message
129by the remote host.
130This is useful if some of the originating hosts can't keep time
131properly or are unable to generate a correct timestamp.
132.It Fl u Ar user
133Set UID to
134.Ar user
135after the sockets and log files have been opened.
136.It Fl U
137Unique priority logging.
138Only log messages at the priority specified by the selector in the
139configuration file.
140Without this option, messages at the specified priority or higher are
141logged.
142This option changes the default priority comparison from
143.Sq \*[Gt]=
144to
145.Sq = .
146.It Fl v
147Verbose logging.
148If specified once, the numeric facility and priority are logged with
149each locally-written message.
150If specified more than once, the names of the facility and priority are
151logged with each locally-written message.
152.El
153.Pp
154.Nm
155reads its configuration file when it starts up and whenever it
156receives a hangup signal.
157For information on the format of the configuration file,
158see
159.Xr syslog.conf 5 .
160.Pp
161.Nm
162reads messages from the
163.Ux
164domain socket
165.Pa /var/run/log ,
166from an Internet domain socket specified in
167.Pa /etc/services ,
168and from the special device
169.Pa /dev/klog
170(to read kernel messages).
171.Pp
172.Nm
173creates the file
174.Pa /var/run/syslogd.pid ,
175and stores its process
176id there.
177This can be used to kill or reconfigure
178.Nm .
179.Pp
180By using multiple
181.Fl p
182options, one can set up many chroot environments by passing the pathname
183to the log socket
184.Pa ( /var/run/log )
185in each chroot area to
186.Nm .
187For example:
188.Dl syslogd -p /var/run/log -p /web/var/run/log -p /ftp/var/run/log
189.Pp
190Note: the normal log socket must now also be passed to
191.Nm .
192.Pp
193The logged message includes the date, time, and hostname (or pathname of
194the log socket).
195Commonly, the program name and the process id is included.
196.Pp
197The date and time are taken from the received message.
198If the format of the timestamp field is incorrect, time obtained from
199the local host is used instead.
200This can be overridden by the
201.Fl T
202flag.
203.Pp
204Accesses from UDP socket can be filtered by libwrap configuration files, like
205.Pa /etc/hosts.deny .
206Specify
207.Dq Li syslogd
208in
209.Ar daemon_list
210portion of the configuration files.
211Refer to
212.Xr hosts_access 5
213for details.
214.Ss SYSLOG PROTOCOL NOTES
215The message sent to
216.Nm
217should consist of a single line.
218The message can contain a priority code, which should be a preceding
219decimal number in angle braces, for example,
220.Sq Aq 5 .
221This priority code should map into the priorities defined in the
222include file
223.Aq Pa sys/syslog.h .
224See RFC 3164 for detailed description of the message format.
225.Pp
226Messages from the local kernel that are not tagged with a priority code
227receive the default facility
228.Dv LOG_KERN
229and priority
230.Dv LOG_NOTICE .
231All other untagged messages receive the default facility
232.Dv LOG_USER
233and priority
234.Dv LOT_NOTICE .
235.Sh FILES
236.Bl -tag -width /var/run/syslogd.pid -compact
237.It Pa /etc/syslog.conf
238The configuration file.
239.It Pa /var/run/syslogd.pid
240The process id of current
241.Nm .
242.It Pa /var/run/log
243Name of the
244.Ux
245domain datagram log socket.
246.It Pa /dev/klog
247The kernel log device.
248.El
249.Sh SEE ALSO
250.Xr logger 1 ,
251.Xr syslog 3 ,
252.Xr services 5 ,
253.Xr syslog.conf 5 ,
254.Xr newsyslog 8
255.Rs
256.%R RFC
257.%N 3164
258.%D August 2001
259.%T The BSD syslog Protocol
260.Re
261.Sh HISTORY
262The
263.Nm
264command appeared in
265.Bx 4.3 .
266Support for multiple log sockets appeared in
267.Nx 1.4 .
268libwrap support appeared in
269.Nx 1.6 .
270