LOGGER(1)							   User Commands							 LOGGER(1)

NAME

       logger - enter messages into the system log

SYNOPSIS

       logger [options] [message]

DESCRIPTION

       logger makes entries in the system log.

       When the optional message argument is present, it is written to the log.  If it is not present, and the -f option is not given either, then
       standard input is logged.

OPTIONS

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

       -e, --skip-empty
	      Ignore empty lines when processing files.  An empty line is defined to be a line without any characters.	 Thus  a  line	consisting
	      only  of	whitespace is NOT considered empty.  Note that when the --prio-prefix option is specified, the priority is not part of the
	      line.  Thus an empty line in this mode is a line that does not have any characters after the priority prefix (e.g. <13>).

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

       -i     Log the PID of the logger process with each line.

       --id[=id]
	      Log the PID of the logger process with each line.  When the optional argument id is specified, then it is used instead of the logger
	      command's PID.  The use of --id=$$ (PPID) is recommended in scripts that send several messages.

	      Note  that the system logging infrastructure (for example systemd when listening on /dev/log) may follow local socket credentials to
	      overwrite the PID specified in the message.  logger(1) is able to set those socket credentials to the given id, but only if you have
	      root  permissions  and a process with the specified PID exists, otherwise the socket credentials are not modified and the problem is
	      silently ignored.

       --journald[=file]
	      Write a systemd journal entry.  The entry is read from the given file, when specified, otherwise from  standard  input.	Each  line
	      must  begin  with a field that is accepted by journald; see systemd.journal-fields(7) for details.  The use of a MESSAGE_ID field is
	      generally a good idea, as it makes finding entries easy.	Examples:

		  logger --journald <<end
		  MESSAGE_ID=67feb6ffbaf24c5cbec13c008dd72309
		  MESSAGE=The dogs bark, but the caravan goes on.
		  DOGS=bark
		  CARAVAN=goes on
		  end

		  logger --journald=entry.txt

	      Notice that --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 journalctl will display MESSAGE field.  Use journalctl --output json-pretty to see rest
	      of the fields.

       --msgid msgid
	      Sets the RFC5424 MSGID field.  Note that the space character is not permitted  inside  of  msgid.   This	option	is  only  used	if
	      --rfc5424 is specified as well; otherwise, it is silently ignored.

       -n, --server server
	      Write  to  the  specified remote syslog server instead of to the system log socket.  Unless --udp or --tcp is specified, logger will
	      first try to use UDP, but if this fails a TCP connection is attempted.

       --no-act
	      Causes everything to be done except for writing the log message to the system log, and removing the connection or the journal.  This
	      option can be used together with --stderr for testing purposes.

       --octet-count
	      Use  the	RFC  6587  octet counting framing method for sending messages.	When this option is not used, the default is no framing on
	      UDP, and RFC6587 non-transparent framing (also known as octet stuffing) on TCP.

       -P, --port port
	      Use the specified port.  When this option is not specified, the port defaults to syslog for udp and to syslog-conn for  tcp  connec-
	      tions.

       -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 local3.info logs the message as informational in the local3 facility.  The default is user.notice.

       --prio-prefix
	      Look for a syslog prefix on every line read from standard input.	This prefix is a decimal number within angle brackets that encodes
	      both  the  facility and the level.  The number is constructed by multiplying the facility by 8 and then adding the level.  For exam-
	      ple, local0.info, meaning 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  pro-
	      vided, the line is logged using the priority given with -p.

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

       --rfc3164
	      Use the RFC 3164 BSD syslog protocol to submit messages to a remote server.

       --rfc5424[=without]
	      Use the RFC 5424 syslog protocol to submit messages to a remote server.  The optional without argument can be a comma-separated list
	      of the following values: notq, notime, nohost.

	      The notq value suppresses the time-quality structured data from the submitted message.  The time-quality information  shows  whether
	      the local clock was synchronized plus the maximum number of microseconds the timestamp might be off.  The time quality is also auto-
	      matically suppressed when --sd-id timeQuality is specified.

	      The notime value (which implies notq) suppresses the complete sender timestamp that is in ISO-8601  format,  including  microseconds
	      and timezone.

	      The nohost value suppresses gethostname(2) information from the message header.

	      The RFC 5424 protocol has been the default for logger since version 2.26.

       -s, --stderr
	      Output the message to standard error as well as to the system log.

       --sd-id name[@digits]
	      Specifies  a  structured data element ID for an RFC 5424 message header.	The option has to be used before --sd-param to introduce a
	      new element.  The number of structured data elements is unlimited.  The ID  (name  plus  possibly  @digits)  is  case-sensitive  and
	      uniquely	identifies the type and purpose of the element.  The same ID must not exist more than once in a message.  The @digits part
	      is required for user-defined non-standardized IDs.

	      logger currently generates the timeQuality standardized element only.  RFC 5424 also describes the elements origin (with	parameters
	      ip,  enterpriseId,  software and swVersion) and meta (with parameters sequenceId, sysUpTime and language).  These element IDs may be
	      specified without the @digits suffix.

       --sd-param name="value"
	      Specifies a structured data element parameter, a name and value pair.  The option has to be used after --sd-id and may be  specified
	      more  than  once	for  the same element.	Note that the quotation marks around value are required and must be escaped on the command
	      line.

		  logger --rfc5424 --sd-id zoo@123		 
				   --sd-param tiger="hungry"	 
				   --sd-param zebra="running"  
				   --sd-id manager@123		 
				   --sd-param onMeeting="yes"  
				   "this is message"

	      produces:

		<13>1 2015-10-01T14:07:59.168662+02:00 ws kzak - - [timeQuality tzKnown="1" isSynced="1" syncAccuracy="218616"][zoo@123 tiger="hungry" zebra="running"][manager@123 onMeeting="yes"] this is message

       --size size
	      Sets the maximum permitted message size to size.	The default is 1KiB characters, which is the limit traditionally used  and  speci-
	      fied in RFC 3164.  With RFC 5424, this limit has become flexible.  A good assumption is that RFC 5424 receivers can at least process
	      4KiB messages.

	      Most receivers accept messages larger than 1KiB over any type of syslog protocol.  As such, the --size option affects logger in  all
	      cases (not only when --rfc5424 was used).

	      Note:  the  message-size	limit  limits  the  overall message size, including the syslog header.	Header sizes vary depending on the
	      selected options and the hostname length.  As a rule of thumb, headers are usually not  longer  than  50	to  80	characters.   When
	      selecting  a maximum message size, it is important to ensure that the receiver supports the max size as well, otherwise messages may
	      become truncated.  Again, as a rule of thumb two to four KiB message size should generally be OK, whereas anything larger should	be
	      verified to work.

       --socket-errors[=mode]
	      Print  errors about Unix socket connections.  The mode can be a value of off, on, or auto.  When the mode is auto logger will detect
	      if the init process is systemd, and if so assumption is made /dev/log can be used  early	at  boot.   Other  init  systems  lack	of
	      /dev/log	will  not  cause  errors that is identical with messaging using openlog(3) system call.  The logger(1) before version 2.26
	      used openlog, and hence was unable to detected loss of messages sent to Unix sockets.

	      The default mode is auto.  When errors are not enabled lost messages are not communicated and will result to successful return value
	      of logger(1) invocation.

       -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.  The default tag is the name of the user logged in on the terminal (or a user
	      name based on effective user ID).

       -u, --socket socket
	      Write to the specified socket instead of to the system log socket.

       --     End the argument list.  This allows the message to start with a hyphen (-).

       -V, --version
	      Display version information and exit.

       -h, --help
	      Display help text and exit.

RETURN VALUE

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

FACILITIES AND LEVELS

       Valid facility names are:

	      auth
	      authpriv	 for security information of a sensitive nature
	      cron
	      daemon
	      ftp
	      kern	 cannot be generated from userspace process, automatically converted to user
	      lpr
	      mail
	      news
	      syslog
	      user
	      uucp
	      local0
		to
	      local7
	      security	 deprecated synonym for auth

       Valid level names are:

	      emerg
	      alert
	      crit
	      err
	      warning
	      notice
	      info
	      debug
	      panic	deprecated synonym for emerg
	      error	deprecated synonym for err
	      warn	deprecated synonym for warning

       For the priority order and intended purposes of these facilities and levels, see syslog(3).

EXAMPLES

       logger System rebooted
       logger -p local0.notice -t HOSTIDM -f /dev/idmc
       logger -n loghost.example.com System rebooted

SEE ALSO

       journalctl(1), syslog(3), systemd.journal-fields(7)

STANDARDS

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

AVAILABILITY

       The logger command is part of the util-linux package and is available from  Linux  Kernel  Archive  <https://www.kernel.org/pub/linux/utils
       /util-linux/>.

util-linux							   November 2015							 LOGGER(1)