Provided by: bsdutils_2.27.1-6ubuntu3.10_amd64 bug


       logger - enter messages into the system log


       logger [options] [message]


       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.


       -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
              When  processing files, empty lines will be ignored. 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 (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.

              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.

              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.

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

                  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.

              Causes  everything  to  be  done except for the write the log message to the system
              log, remove connection or journal. This options is usable  together  with  --stderr
              for testing purpose.

       --size size
              Sets  the  maximum  permitted message size to size. The default is 1KiB characters,
              which is the limit traditionally used and specified 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 larger than 1KiB message over any type of syslog protocol. As
              such,  the  --size  option affects logger in all cases (not only when --rfc5424 was

              Note: the message size limit limits the overall message size, including the  syslog
              header.  Header  sizes vary depending on options selected and hostname length. As a
              rule of thumb, headers are usually not  longer  than  50  to  80  characters.  When
              selecting  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.

       -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 thist
              fails a TCP connection is attempted.

       -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 connections.

       -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

              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 example,, 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 provided, the line is logged  using  the
              priority given with -p.

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

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

              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 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.

              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.

       -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 system log socket.

              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 inable 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.

       --     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.


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


       Valid facility names are:

              authpriv   for security information of a sensitive nature
              kern       cannot be generated from userspace process, automatically converted to user
              security   deprecated synonym for auth

       Valid level names are:


              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


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


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


       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 ⟨⟩.