noble (1) logger.1.gz

Provided by: bsdutils_2.39.3-9ubuntu6.2_amd64 bug

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.

           See also --server and --socket to specify where to connect.

       -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(1) will display
           MESSAGE field. Use journalctl --output json-pretty to see rest of the fields.

           To include newlines in MESSAGE, specify MESSAGE several times. This is handled as a special case,
           other fields will be stored as an array in the journal if they appear multiple times.

       --msgid msgid
           Sets the RFC 5424 <https://tools.ietf.org/html/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 to the journal. This option can be used together with --stderr for testing purposes.

       --octet-count
           Use the RFC 6587 <https://tools.ietf.org/html/rfc6587> 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 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 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 example, 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 provided, the line is logged using the priority given with -p.

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

       --rfc3164
           Use the RFC 3164 <https://tools.ietf.org/html/rfc3164> BSD syslog protocol to submit messages to a
           remote server.

       --rfc5424[=without]
           Use the RFC 5424 <https://tools.ietf.org/html/rfc5424> 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 automatically 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

       -S, --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 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, then logger will detect if the init process is systemd(1), 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(3), 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 exit status 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.

           See also --server and --socket to specify where to connect.

       -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 (-).

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

       -V, --version
           Print version and exit.

EXIT STATUS

       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).

CONFORMING TO

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

EXAMPLES

          logger System rebooted

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

          logger -n loghost.example.com System rebooted

AUTHORS

       The logger command was originally written by University of California in 1983-1993 and later rewritten by
       Karel Zak <kzak@redhat.com>, Rainer Gerhards <rgerhards@adiscon.com>, and Sami Kerola <kerolasa@iki.fi>.

SEE ALSO

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

REPORTING BUGS

       For bug reports, use the issue tracker at https://github.com/util-linux/util-linux/issues.

AVAILABILITY

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