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.\"     @(#)syslogd.8	8.1 (Berkeley) 6/6/93
.\"
.Dd February 9, 2019
.Dt SYSLOGD 8 SMM
.Os "GNU Network Utilities"
.Sh NAME
.Nm syslogd
.Nd log systems messages
.Sh SYNOPSIS
.Nm syslogd
.Op Ar options ...
.Sh DESCRIPTION
.Nm syslogd
reads and logs messages to the system console, log files, other
machines and/or users as specified by its configuration file.
.Sh OPTIONS
.Bl -tag -width Ds
.It Fl 4 , -ipv4
Restrict to IPv4 transport (default).
.It Fl 6 , -ipv6
Restrict to IPv6 transport.
.It Fl -ipany
Allow transport with IPv4 and IPv6.
.It Fl a Ar socket
Specify additional sockets from that syslogd has to listen to.
This is needed if you are going to let some daemon run within
a chroot()'ed environment. You can specify up to 19 additional
sockets.
.It Fl b , -bind Ar addr
Bind listener to this address/name.
.It Fl B , -bind-port Ar port
Bind listener to this port.
.It Fl f , -rcfile Ar file
Specify the pathname of an alternate configuration file;
the default is system specific and displayed in the help output.
.It Fl D , -rcdir Ar dir
Specify the pathname of an alternate configuration directory;
the default is system specific and displayed in the help output.
.It Fl h , -hop
Enable forwarding remote messages. By default syslogd will not
forward messages it receives from remote hosts.
.It Fl l Ar host_list
A colon-seperated lists of hosts which should be considered local;
they are logged by their hostnames instead by their FQDN.
.It Fl s Ar domain_list
A colon-seperated list of domainnames which should be stripped from
the FQDNs of hosts when logging.
.It Fl m , -mark Ar interval
Select the number of minutes between "mark" messages;
the default is 20 minutes. Setting it to 0 disables timestamps.
.It Fl p , -socket Ar path
Specify the pathname of an alternate log socket.
The default is system specific and displayed in the help output.
.It Fl r , -inet
Enable to receive remote messages using an internet domain socket.
The default is to not receive any messages from the network. Older
version always accepted remote messages.
.It Fl T , -local-time
Set local time on received messages.
.It Fl S , -sync
Force a file sync on every line.
.It Fl n , -no-detach
Suppress backgrounding and detachment of the daemon from its
controlling terminal.
.It Fl -no-klog
Do not listen to the kernel log device. This is only supported on
systems which define a kernel log device, on all others this is already
the default, and the option will be silently ignored.
.It Fl -no-unixaf
Do not listen to any unix domain socket. This option overrides \-p and \-a.
.It Fl -no-forward
Do not forward any messages. This overrides \-h.
.It Fl d , -debug
Enter debug mode. syslogd does not put itself in the background, does
not fork and shows debug information.
.It Fl ? , -help
Display help information and exit.
.It Fl -usage
Display a short usage message and exit.
.It Fl V , -version
Print version number and exit.
.El
.Pp
.Nm syslogd
reads its configuration file when it starts up and whenever it
receives a hangup signal.
For information on the format of the configuration file,
see
.Xr syslog.conf 5 .
.Pp
.Nm syslogd
reads messages from the
.Tn UNIX
domain socket
.Pa /dev/log ,
from an Internet domain socket specified in
.Pa /etc/services ,
and from the one of the special devices
.Pa /dev/klog
or
.Pa /proc/kmsg
depending on the system (to read kernel messages). In a GNU/Linux system
it will not parse the System.map and use it to annotate the kernel messages.
.Pp
.Nm syslogd
creates the file
.Pa /var/run/syslog.pid ,
and stores its process
id there.
This can be used to kill or reconfigure
.Nm syslogd .
.Pp
The message sent to
.Nm syslogd
should consist of a single line.
The message can contain a priority code, which should be a preceding
decimal number in angle braces, for example,
.Sq Aq 5.
This priority code should map into the priorities defined in the
include file
.Aq Pa sys/syslog.h .
.Sh FILES
.Bl -tag -width /var/run/syslog.pid -compact
.It Pa /etc/syslog.conf
The configuration file.
.It Pa /var/run/syslog.pid
The process id of current
.Nm syslogd .
.It Pa /dev/log
Name of the
.Tn UNIX
domain datagram log socket.
.It Pa /dev/klog, /proc/kmsg
The kernel log device.
.El
.Sh SEE ALSO
.Xr logger 1 ,
.Xr syslog 3 ,
.Xr services 5 ,
.Xr syslog.conf 5
.Sh HISTORY
The
.Nm
command appeared in
.Bx 4.3 .