systemd-cat(1) — Linux manual page


SYSTEMD-CAT(1)                 systemd-cat                SYSTEMD-CAT(1)

NAME         top

       systemd-cat - Connect a pipeline or program's output with the

SYNOPSIS         top

       systemd-cat [OPTIONS...] [COMMAND] [ARGUMENTS...]

       systemd-cat [OPTIONS...]

DESCRIPTION         top

       systemd-cat may be used to connect the standard input and output
       of a process to the journal, or as a filter tool in a shell
       pipeline to pass the output the previous pipeline element
       generates to the journal.

       If no parameter is passed, systemd-cat will write everything it
       reads from standard input (stdin) to the journal.

       If parameters are passed, they are executed as command line with
       standard output (stdout) and standard error output (stderr)
       connected to the journal, so that all it writes is stored in the

OPTIONS         top

       The following options are understood:

       -h, --help
           Print a short help text and exit.

           Print a short version string and exit.

       -t, --identifier=
           Specify a short string that is used to identify the logging
           tool. If not specified, no identification string is written
           to the journal.

       -p, --priority=
           Specify the default priority level for the logged messages.
           Pass one of "emerg", "alert", "crit", "err", "warning",
           "notice", "info", "debug", or a value between 0 and 7
           (corresponding to the same named levels). These priority
           values are the same as defined by syslog(3). Defaults to
           "info". Note that this simply controls the default,
           individual lines may be logged with different levels if they
           are prefixed accordingly. For details, see --level-prefix=

           Specifies the default priority level for messages from the
           process's standard error output (stderr). Usage of this
           option is the same as the --priority= option, above, and both
           can be used at once. When both are used, --priority= will
           specify the default priority for standard output (stdout).

           If --stderr-priority= is not specified, messages from stderr
           will still be logged, with the same default priority level as

           Also, note that when stdout and stderr use the same default
           priority, the messages will be strictly ordered, because one
           channel is used for both. When the default priority differs,
           two channels are used, and so stdout messages will not be
           strictly ordered with respect to stderr messages - though
           they will tend to be approximately ordered.

           Added in version 241.

           Controls whether lines read are parsed for syslog priority
           level prefixes. If enabled (the default), a line prefixed
           with a priority prefix such as "<5>" is logged at priority 5
           ("notice"), and similarly for the other priority levels.
           Takes a boolean argument.

EXIT STATUS         top

       On success, 0 is returned, a non-zero failure code otherwise.

EXAMPLES         top

       Example 1. Invoke a program

       This calls /bin/ls with standard output and error connected to
       the journal:

           # systemd-cat ls

       Example 2. Usage in a shell pipeline

       This builds a shell pipeline also invoking /bin/ls and writes the
       output it generates to the journal:

           # ls | systemd-cat

       Even though the two examples have very similar effects, the first
       is preferable, since only one process is running at a time and
       both stdout and stderr are captured, while in the second example,
       only stdout is captured.

SEE ALSO         top

       systemd(1), systemctl(1), logger(1)

COLOPHON         top

       This page is part of the systemd (systemd system and service
       manager) project.  Information about the project can be found at
       ⟨⟩.  If you have
       a bug report for this manual page, see
       This page was obtained from the project's upstream Git repository
       ⟨⟩ on 2023-12-22.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2023-12-22.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to

systemd 255                                               SYSTEMD-CAT(1)

Pages that refer to this page: journalctl(1)sd-journal(3)systemd.directives(7)systemd.index(7)systemd-journald.service(8)