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.
The following options are understood:
Print a short help text and exit.
Print a short version string and exit.
Specify a short string that is used to identify the logging tool.
If not specified, no identification string is written to the
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
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
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.
This page is part of the systemd (systemd system and service manager)
project. Information about the project can be found at
⟨http://www.freedesktop.org/wiki/Software/systemd⟩. If you have a bug
report for this manual page, see
page was obtained from the project's upstream Git repository
⟨https://github.com/systemd/systemd.git⟩ on 2016-09-01. If you dis‐
cover 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
systemd 231 SYSTEMD-CAT(1)