systemd-cat Man page

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


systemd-cat – Connect a pipeline or program’s output with the journal



systemd-cat [OPTIONS…]


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 journal.


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=

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 argument.

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

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


systemd, systemctl, logger

systemd 229 SYSTEMD-CAT(1)