systemd-stable/man/systemd-cat.xml

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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
        "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">

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<refentry id="systemd-cat"
          xmlns:xi="http://www.w3.org/2001/XInclude">

        <refentryinfo>
                <title>systemd-cat</title>
                <productname>systemd</productname>

                <authorgroup>
                        <author>
                                <contrib>Developer</contrib>
                                <firstname>Lennart</firstname>
                                <surname>Poettering</surname>
                                <email>lennart@poettering.net</email>
                        </author>
                </authorgroup>
        </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><refentrytitle>logger</refentrytitle><manvolnum>1</manvolnum></citerefentry>
                </para>
        </refsect1>

</refentry>