1.\"	$OpenBSD: syslogd.8,v 1.21 2004/12/02 21:58:57 jmc Exp $
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30.\"     from: @(#)syslogd.8	8.1 (Berkeley) 6/6/93
31.\"	$NetBSD: syslogd.8,v 1.3 1996/01/02 17:41:48 perry Exp $
32.\"
33.Dd June 6, 1993
34.Dt SYSLOGD 8
35.Os
36.Sh NAME
37.Nm syslogd
38.Nd log systems messages
39.Sh SYNOPSIS
40.Nm syslogd
41.Bk -words
42.Op Fl dnu
43.Op Fl a Ar path
44.Op Fl f Ar config_file
45.Op Fl m Ar mark_interval
46.Op Fl p Ar log_socket
47.Op Fl s Ar reporting_socket
48.Ek
49.Sh DESCRIPTION
50.Nm
51reads and logs messages to the system console, log files, other
52machines and/or users as specified by its configuration file.
53.Pp
54The options are as follows:
55.Bl -tag -width Ds
56.It Fl a Pa path
57Specify a location where
58.Nm
59should place an additional log socket.
60Up to about 20 additional logging sockets can be specified.
61The primary use for this is to place additional log sockets in
62.Pa /dev/log
63of various chroot filespaces.
64.It Fl d
65Enable debugging to the standard output,
66and do not disassociate from the controlling terminal.
67.It Fl f Ar config_file
68Specify the pathname of an alternate configuration file;
69the default is
70.Pa /etc/syslog.conf .
71.It Fl m Ar mark_interval
72Select the number of minutes between
73.Dq mark
74messages; the default is 20 minutes.
75.It Fl n
76Print source addresses numerically rather than symbolically.
77This saves an address-to-name lookup for each incoming message,
78which can be useful when combined with the
79.Fl u
80option on a loghost with no DNS cache.
81Messages from the local host will still be logged with
82the symbolic local host name.
83.It Fl p Ar log_socket
84Specify the pathname of an alternate log socket to be used instead;
85the default is
86.Pa /dev/log .
87.It Fl s Ar reporting_socket
88Specify path to an
89.Dv AF_LOCAL
90socket for use in reporting logs stored in memory buffers using
91.Xr syslogc 8 .
92.It Fl u
93Select the historical
94.Dq insecure
95mode, in which syslogd will
96accept input from the UDP port.
97Some software wants this, but you can be subjected to a variety of
98attacks over the network, including attackers remotely filling logs.
99.El
100.Pp
101.Nm
102reads its configuration file when it starts up and whenever it
103receives a hangup signal.
104For information on the format of the configuration file,
105see
106.Xr syslog.conf 5 .
107.Pp
108.Nm
109creates the file
110.Pa /var/run/syslog.pid ,
111and stores its process ID there.
112This can be used to kill or reconfigure
113.Nm syslogd .
114.Pp
115.Nm
116opens an Internet domain socket as specified
117in
118.Pa /etc/services .
119Normally
120.Nm
121will only use this socket to send messages outwards, but in
122.Dq insecure
123mode it will also read messages from this socket.
124.Nm
125also opens and reads messages from the
126.Tn UNIX
127domain socket
128.Pa /dev/log ,
129and from the special device
130.Pa /dev/klog
131(to read kernel messages).
132.Pp
133.Nm
134opens the above described socket whether or not it is
135running in secure mode.
136If
137.Nm
138is running in secure mode, all incoming data on this socket is discarded.
139The socket is required for sending forwarded messages.
140.Pp
141The message sent to
142.Nm
143should consist of a single line.
144The message can contain a priority code, which should be a preceding
145decimal number in angle braces, for example,
146.Dq Aq 5 .
147This priority code should map into the priorities defined in the
148include file
149.Aq Pa sys/syslog.h .
150.Sh FILES
151.Bl -tag -width /var/run/syslog.pid -compact
152.It Pa /etc/syslog.conf
153configuration file
154.It Pa /var/run/syslog.pid
155process ID of current
156.Nm syslogd
157.It Pa /dev/log
158name of the
159.Tn UNIX
160domain datagram log socket
161.It Pa /dev/klog
162kernel log device
163.El
164.Sh SEE ALSO
165.Xr logger 1 ,
166.Xr syslog 3 ,
167.Xr services 5 ,
168.Xr syslog.conf 5 ,
169.Xr newsyslog 8 ,
170.Xr syslogc 8
171.Sh HISTORY
172The
173.Nm
174command appeared in
175.Bx 4.3 .
176