Systemd/man/systemd-cat.xml

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<?xml version='1.0'?> <!--*-nxml-*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<!--
SPDX-License-Identifier: LGPL-2.1+
-->
<refentry id="systemd-cat"
xmlns:xi="http://www.w3.org/2001/XInclude">
<refentryinfo>
<title>systemd-cat</title>
<productname>systemd</productname>
</refentryinfo>
<refmeta>
<refentrytitle>systemd-cat</refentrytitle>
<manvolnum>1</manvolnum>
</refmeta>
<refnamediv>
<refname>systemd-cat</refname>
<refpurpose>Connect a pipeline or program's output with the journal</refpurpose>
</refnamediv>
<refsynopsisdiv>
<cmdsynopsis>
<command>systemd-cat <arg choice="opt" rep="repeat">OPTIONS</arg> <arg>COMMAND</arg> <arg choice="opt" rep="repeat">ARGUMENTS</arg></command>
</cmdsynopsis>
<cmdsynopsis>
<command>systemd-cat <arg choice="opt" rep="repeat">OPTIONS</arg></command>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para><command>systemd-cat</command> 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.</para>
<para>If no parameter is passed, <command>systemd-cat</command>
will write everything it reads from standard input (stdin) to the
journal.</para>
<para>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.</para>
</refsect1>
<refsect1>
<title>Options</title>
<para>The following options are understood:</para>
<variablelist>
<xi:include href="standard-options.xml" xpointer="help" />
<xi:include href="standard-options.xml" xpointer="version" />
<varlistentry>
<term><option>-t</option></term>
<term><option>--identifier=</option></term>
<listitem><para>Specify a short string that is used to
identify the logging tool. If not specified, no identification
string is written to the journal.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-p</option></term>
<term><option>--priority=</option></term>
<listitem><para>Specify the default priority level for the
logged messages. Pass one of
<literal>emerg</literal>,
<literal>alert</literal>,
<literal>crit</literal>,
<literal>err</literal>,
<literal>warning</literal>,
<literal>notice</literal>,
<literal>info</literal>,
<literal>debug</literal>, or a
value between 0 and 7 (corresponding to the same named
levels). These priority values are the same as defined by
<citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
Defaults to <literal>info</literal>. Note that this simply
controls the default, individual lines may be logged with
different levels if they are prefixed accordingly. For details,
see <option>--level-prefix=</option> below.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--level-prefix=</option></term>
<listitem><para>Controls whether lines read are parsed for
syslog priority level prefixes. If enabled (the default), a
line prefixed with a priority prefix such as
<literal>&lt;5&gt;</literal> is logged at priority 5
(<literal>notice</literal>), and similar for the other
priority levels. Takes a boolean argument.</para></listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Exit status</title>
<para>On success, 0 is returned, a non-zero failure code
otherwise.</para>
</refsect1>
<refsect1>
<title>Examples</title>
<example>
<title>Invoke a program</title>
<para>This calls <filename noindex='true'>/bin/ls</filename>
with standard output and error connected to the journal:</para>
<programlisting># systemd-cat ls</programlisting>
</example>
<example>
<title>Usage in a shell pipeline</title>
<para>This builds a shell pipeline also invoking
<filename>/bin/ls</filename> and writes the output it generates
to the journal:</para>
<programlisting># ls | systemd-cat</programlisting>
</example>
<para>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.</para>
</refsect1>
<refsect1>
<title>See Also</title>
<para>
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry project='man-pages'><refentrytitle>logger</refentrytitle><manvolnum>1</manvolnum></citerefentry>
</para>
</refsect1>
</refentry>