logger — a shell command interface to the syslog(3) system log module


logger [options] [message]


logger makes entries in the system log. It provides a shell command interface to the syslog(3) system log module.


−d, −−udp

Use datagram (UDP) only. By default the connection is tried to the syslog port defined in /etc/services, which is often 514.

−h, −−help

Display help text and exit.

−i, −−id

Log the process ID of the logger process with each line.

−n, −−server server

Write to the specified remote syslog server instead of to the builtin syslog routines. Unless −−udp or −−tcp is specified, logger will first try to use UDP, but if thist fails a TCP connection is attempted.

−P, −−port port

Use the specified port. −f, −−file file Log the contents of the specified file. This option cannot be combined with a command-line message.

−p, −−priority priority

Enter the message into the log with the specified priority. The priority may be specified numerically or as a facility.level pair. For example, −p logs the message as informational in the local3 facility. The default is user.notice.


Look for a syslog prefix on every line read from standard input. This prefix is a number within angle brackets that contains both the facility and the level. This decimal prefix is constructed by multiplying the facility by 8 and then adding the level. Thus, for example,, facility=16 and level=6, becomes <134>.

If the prefix contains no facility, the facility defaults to what is specified by the −p option. Similarly, if no prefix is provided, the line is logged using the −p priority.

This option doesn't affect a command-line message.

−s, −−stderr

Output the message to standard error as well as to the system log.

−T, −−tcp

Use stream (TCP) only. By default the connection is tried to the syslog-conn port defined in /etc/services, which is often 601.

−t, −−tag tag

Mark every line to be logged with the specified tag.

−u, −−socket socket

Write to the specified socket instead of to the builtin syslog routines.

−V, −−version

Display version information and exit.


End the argument list. This is to allow the message to start with a hyphen (−).


Write this message to the log; if not specified, and the −f flag is not provided, standard input is logged.

The logger utility exits 0 on success, and >0 if an error occurs.

Valid facility names are: auth,authpriv (for security information of a sensitive nature), cron,daemon,ftp,kern (can't be generated from user process), lpr,mail,news,security (deprecated synonym for auth),syslog,user,uucp, and local0tolocal7, inclusive.

Valid level names are: alert,crit,debug,emerg,err,error (deprecated synonym for err),info,notice,panic (deprecated synonym for emerg),warning,warn (deprecated synonym for warning). For the priority order and intended purposes of these levels, see syslog(3).


logger System rebooted

logger −p local0.notice −t HOSTIDM −f /dev/idmc

logger −n System rebooted


syslog(3), syslogd(8)


The logger command is expected to be IEEE Std 1003.2 ("POSIX.2") compatible.


The logger command is part of the util-linux package and is available from Linux Kernel Archive

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(#)logger.1 8.1 (Berkeley) 6/6/93

Section on valid facility and level strings added by, 26 Oct 1997.