man/systemd-cat.xml

   1 <?xml version='1.0'?> <!--*-nxml-*-->
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
   3   "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
   4
   5 <!--
   6   SPDX-License-Identifier: LGPL-2.1+
   7
   8   This file is part of systemd.
   9
  10   Copyright 2012 Lennart Poettering
  11 -->
  12
  13 <refentry id="systemd-cat"
  14     xmlns:xi="http://www.w3.org/2001/XInclude">
  15
  16   <refentryinfo>
  17     <title>systemd-cat</title>
  18     <productname>systemd</productname>
  19
  20     <authorgroup>
  21       <author>
  22         <contrib>Developer</contrib>
  23         <firstname>Lennart</firstname>
  24         <surname>Poettering</surname>
  25         <email>lennart@poettering.net</email>
  26       </author>
  27     </authorgroup>
  28   </refentryinfo>
  29
  30   <refmeta>
  31     <refentrytitle>systemd-cat</refentrytitle>
  32     <manvolnum>1</manvolnum>
  33   </refmeta>
  34
  35   <refnamediv>
  36     <refname>systemd-cat</refname>
  37     <refpurpose>Connect a pipeline or program's output with the journal</refpurpose>
  38   </refnamediv>
  39
  40   <refsynopsisdiv>
  41     <cmdsynopsis>
  42       <command>systemd-cat <arg choice="opt" rep="repeat">OPTIONS</arg> <arg>COMMAND</arg> <arg choice="opt" rep="repeat">ARGUMENTS</arg></command>
  43     </cmdsynopsis>
  44     <cmdsynopsis>
  45       <command>systemd-cat <arg choice="opt" rep="repeat">OPTIONS</arg></command>
  46     </cmdsynopsis>
  47   </refsynopsisdiv>
  48
  49   <refsect1>
  50     <title>Description</title>
  51
  52     <para><command>systemd-cat</command> may be used to connect the
  53     standard input and output of a process to the journal, or as a
  54     filter tool in a shell pipeline to pass the output the previous
  55     pipeline element generates to the journal.</para>
  56
  57     <para>If no parameter is passed, <command>systemd-cat</command>
  58     will write everything it reads from standard input (stdin) to the
  59     journal.</para>
  60
  61     <para>If parameters are passed, they are executed as command line
  62     with standard output (stdout) and standard error output (stderr)
  63     connected to the journal, so that all it writes is stored in the
  64     journal.</para>
  65   </refsect1>
  66
  67   <refsect1>
  68     <title>Options</title>
  69
  70     <para>The following options are understood:</para>
  71
  72     <variablelist>
  73       <xi:include href="standard-options.xml" xpointer="help" />
  74       <xi:include href="standard-options.xml" xpointer="version" />
  75
  76       <varlistentry>
  77         <term><option>-t</option></term>
  78         <term><option>--identifier=</option></term>
  79
  80         <listitem><para>Specify a short string that is used to
  81         identify the logging tool. If not specified, no identification
  82         string is written to the journal.</para></listitem>
  83       </varlistentry>
  84
  85       <varlistentry>
  86         <term><option>-p</option></term>
  87         <term><option>--priority=</option></term>
  88
  89         <listitem><para>Specify the default priority level for the
  90         logged messages. Pass one of
  91         <literal>emerg</literal>,
  92         <literal>alert</literal>,
  93         <literal>crit</literal>,
  94         <literal>err</literal>,
  95         <literal>warning</literal>,
  96         <literal>notice</literal>,
  97         <literal>info</literal>,
  98         <literal>debug</literal>, or a
  99         value between 0 and 7 (corresponding to the same named
 100         levels). These priority values are the same as defined by
 101         <citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
 102         Defaults to <literal>info</literal>. Note that this simply
 103         controls the default, individual lines may be logged with
 104         different levels if they are prefixed accordingly. For details,
 105         see <option>--level-prefix=</option> below.</para></listitem>
 106       </varlistentry>
 107
 108       <varlistentry>
 109         <term><option>--level-prefix=</option></term>
 110
 111         <listitem><para>Controls whether lines read are parsed for
 112         syslog priority level prefixes. If enabled (the default), a
 113         line prefixed with a priority prefix such as
 114         <literal>&lt;5&gt;</literal> is logged at priority 5
 115         (<literal>notice</literal>), and similar for the other
 116         priority levels. Takes a boolean argument.</para></listitem>
 117       </varlistentry>
 118
 119     </variablelist>
 120
 121   </refsect1>
 122
 123   <refsect1>
 124     <title>Exit status</title>
 125
 126     <para>On success, 0 is returned, a non-zero failure code
 127     otherwise.</para>
 128   </refsect1>
 129
 130   <refsect1>
 131     <title>Examples</title>
 132
 133     <example>
 134       <title>Invoke a program</title>
 135
 136       <para>This calls <filename noindex='true'>/bin/ls</filename>
 137       with standard output and error connected to the journal:</para>
 138
 139       <programlisting># systemd-cat ls</programlisting>
 140     </example>
 141
 142     <example>
 143       <title>Usage in a shell pipeline</title>
 144
 145       <para>This builds a shell pipeline also invoking
 146       <filename>/bin/ls</filename> and writes the output it generates
 147       to the journal:</para>
 148
 149       <programlisting># ls | systemd-cat</programlisting>
 150     </example>
 151
 152     <para>Even though the two examples have very similar effects the
 153     first is preferable since only one process is running at a time,
 154     and both stdout and stderr are captured while in the second
 155     example, only stdout is captured.</para>
 156   </refsect1>
 157
 158   <refsect1>
 159     <title>See Also</title>
 160     <para>
 161       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 162       <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 163       <citerefentry project='man-pages'><refentrytitle>logger</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 164     </para>
 165   </refsect1>
 166
 167 </refentry>