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 journal

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

       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 journal.

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

       -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= below.

           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 stdout.

           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.

           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 similar for the other priority levels. Takes a boolean

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

           # 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 2020-09-18.  (At that
       time, the date of the most recent commit that was found in the repos‐
       itory was 2020-09-18.)  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 246                                                   SYSTEMD-CAT(1)

Pages that refer to this page: sd-journal(3)30-systemd-environment-d-generator(7)systemd.directives(7)systemd.index(7)systemd-journald(8)systemd-journald-audit.socket(8)systemd-journald-dev-log.socket(8)systemd-journald.service(8)systemd-journald@.service(8)systemd-journald.socket(8)systemd-journald@.socket(8)systemd-journald-varlink.socket(8)systemd-journald-varlink@.socket(8)