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