SYSLOGD(8) System Manager’s Manual SYSLOGD(8)


syslogd — log systems messages


syslogd [options ...]


syslogd reads and logs messages to the system console, log files, other machines and/or users as specified by its configuration file.

, --ipv4

Restrict to IPv4 transport (default).

-6, --ipv6

Restrict to IPv6 transport.


Allow transport with IPv4 and IPv6.

-a 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.

-b, --bind addr

Bind listener to this address/name.

-B, --bind-port port

Bind listener to this port.

-f, --rcfile file

Specify the pathname of an alternate configuration file; the default is system specific and displayed in the help output.

-D, --rcdir dir

Specify the pathname of an alternate configuration directory; the default is system specific and displayed in the help output.

-h, --hop

Enable forwarding remote messages. By default syslogd will not forward messages it receives from remote hosts.

-l host_list

A colon-seperated lists of hosts which should be considered local; they are logged by their hostnames instead by their FQDN.

-s domain_list

A colon-seperated list of domainnames which should be stripped from the FQDNs of hosts when logging.

-m, --mark interval

Select the number of minutes between ’’mark’’ messages; the default is 20 minutes. Setting it to 0 disables timestamps.

-p, --socket path

Specify the pathname of an alternate log socket. The default is system specific and displayed in the help output.

-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.

-T, --local-time

Set local time on received messages.

-S, --sync

Force a file sync on every line.

-n, --no-detach

Suppress backgrounding and detachment of the daemon from its controlling terminal.


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.


Do not listen to any unix domain socket. This option overrides -p and -a.


Do not forward any messages. This overrides -h.

-d, --debug

Enter debug mode. syslogd does not put itself in the background, does not fork and shows debug information.

-?, --help

Display help information and exit.


Display a short usage message and exit.

-V, --version

Print version number and exit.

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 syslog.conf(5).

syslogd reads messages from the UNIX domain socket /dev/log, from an Internet domain socket specified in /etc/services, and from the one of the special devices /dev/klog or /proc/kmsg depending on the system (to read kernel messages). In a GNU/Linux system it will not parse the and use it to annotate the kernel messages.

syslogd creates the file /var/run/, and stores its process id there. This can be used to kill or reconfigure syslogd.

The message sent to 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, ’⟨ 5.⟩ ’ This priority code should map into the priorities defined in the include file ⟨ sys/syslog.h⟩ .


The configuration file.


The process id of current syslogd.


Name of the UNIX domain datagram log socket.

/dev/klog, /proc/kmsg

The kernel log device.


logger(1), syslog(3), services(5), syslog.conf(5)


The syslogd command appeared in 4.3BSD.

GNU Network Utilities February 9, 2019 GNU Network Utilities