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.\"	@(#)logger.1	8.1 (Berkeley) 6/6/93
.\"
.\" Section on valid facility and level strings added by
.\" and1000@debian.org, 26 Oct 1997.
.TH LOGGER "1" "April 2013" "util-linux" "User Commands"
.SH NAME
logger \- a shell command interface to the syslog(3) system log module
.SH SYNOPSIS
.B logger
.RI [ options "] [" message ]
.SH DESCRIPTION
.B logger
makes entries in the system log.  It provides a shell command
interface to the
.BR syslog (3)
system log module.
.SH OPTIONS
.TP
\fB\-d\fR, \fB\-\-udp\fR
Use datagram (UDP) only.  By default the connection is tried to the
.I syslog
port defined in /etc/services, which is often
.IR 514 .
.TP
\fB\-h\fR, \fB\-\-help\fR
Display help text and exit.
.TP
\fB\-i\fR, \fB\-\-id\fR
Log the process ID of the logger process with each line.
.TP
.TP
\fB\-n\fR, \fB\-\-server\fR \fIserver\fR
Write to the specified remote syslog
.I server
instead of to the builtin syslog routines.  Unless
.B \-\-udp
or
.B \-\-tcp
is specified, \fBlogger\fR will first try to use UDP,
but if thist fails a TCP connection is attempted.
.TP
\fB\-P\fR, \fB\-\-port\fR \fIport\fR
Use the specified
.IR port .
.TP
\fB\-f\fR, \fB\-\-file\fR \fIfile\fR
Log the contents of the specified
.IR file .
This option cannot be combined with a command-line message.
.TP
\fB\-p\fR, \fB\-\-priority\fR \fIpriority\fR
Enter the message into the log with the specified
.IR priority  .
The priority may be specified numerically or as a
.I facility.level
pair.
For example,
.B -p
.I local3.info
logs the message as informational in the local3 facility.
The default is
.IR user.notice .
.TP
\fB\-\-prio\-prefix\fR
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, \fIlocal0.info\fR,
facility=16 and level=6, becomes \fI<134>\fR.

If the prefix contains no facility, the facility defaults to what is
specified by the \fB\-p\fR option.  Similarly, if no prefix is provided,
the line is logged using the \fB\-p\fR \fIpriority\fR.

This option doesn't affect a command-line message.
.TP
\fB\-s\fR, \fB\-\-stderr\fR
Output the message to standard error as well as to the system log.
.TP
\fB\-T\fR, \fB\-\-tcp\fR
Use stream (TCP) only.  By default the connection is tried to the
.I syslog-conn
port defined in /etc/services, which is often
.IR 601 .
.TP
\fB\-t\fR, \fB\-\-tag\fR \fItag\fR
Mark every line to be logged with the specified
.IR tag .
.TP
\fB\-u\fR, \fB\-\-socket\fR \fIsocket\fR
Write to the specified
.I socket
instead of to the builtin syslog routines.
.TP
\fB\-\-journald\fR [\fIfile\fR]
Write systemd journal entry.  The entry is read from
.I stdin
or input
.IR file .
Each new line must begin with a field that is accepted by journald, see
.IR systemd.journal-fields (7)
for details.  Use of MESSAGE_ID field is generally good idea, as they
make finding entries easy.
.IP
.nf
$ printf "%s\\n%s\\n%s\\n" MESSAGE_ID=86184c3b1aa444f58ebe7b30fec1438b DOGS=bark "CARAVAN=goes on" | logger --journald
$ logger --journald=entry.txt
.fi
.IP
Notice that
.B \-\-journald
will ignore values of other options, such as priority.  If priority is
needed it must be within input, and use PRIORITY field.  The simple
execution of
.B journalctl
will display MESSAGE field.  Use
.B journalctl --output json-pretty
to see rest of the fields.
.TP
\fB\-V\fR, \fB\-\-version\fR
Display version information and exit.
.TP
\fB\-\-\fR
End the argument list.  This is to allow the
.I message
to start with a hyphen (\-).
.TP
.I message
Write this \fImessage\fR to the log; if not specified, and the
.B \-f
flag is not provided, standard input is logged.
.PP
The
.B logger
utility exits 0 on success, and >0 if an error occurs.
.PP
Valid facility names are:
.IR auth , \ authpriv
(for security information of a sensitive nature),
.IR cron , \ daemon , \ ftp , \ kern
(can't be generated from user process),
.IR lpr , \ mail , \ news , \ security
(deprecated synonym for
.IR auth ), \ syslog , \ user , \ uucp ,
and
.IR local0 \ to \ local7 ,
inclusive.
.PP
Valid level names are:
.IR alert , \ crit , \ debug , \ emerg , \ err , \ error
(deprecated synonym for
.IR err ), \ info , \ notice , \ panic
(deprecated synonym for
.IR  emerg ), \ warning , \ warn
(deprecated synonym for
.IR warning ).
For the priority order and intended purposes of these levels, see
.BR syslog (3).
.SH EXAMPLES
logger System rebooted
.br
logger \-p local0.notice \-t HOSTIDM \-f /dev/idmc
.br
logger \-n loghost.example.com System rebooted
.SH SEE ALSO
.BR syslog (3),
.BR syslogd (8),
.BR journalctl (1),
.BR systemd.journal-fields (7)
.SH STANDARDS
The
.B logger
command is expected to be IEEE Std 1003.2 ("POSIX.2") compatible.
.SH AVAILABILITY
The logger command is part of the util-linux package and is available from
.UR ftp://\:ftp.kernel.org\:/pub\:/linux\:/utils\:/util-linux/
Linux Kernel Archive
.UE .