man/journalctl.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
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   6   This file is part of systemd.
   7
   8   Copyright 2012 Lennart Poettering
   9
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  11   under the terms of the GNU General Public License as published by
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  23
  24 <refentry id="journalctl">
  25
  26         <refentryinfo>
  27                 <title>journalctl</title>
  28                 <productname>systemd</productname>
  29
  30                 <authorgroup>
  31                         <author>
  32                                 <contrib>Developer</contrib>
  33                                 <firstname>Lennart</firstname>
  34                                 <surname>Poettering</surname>
  35                                 <email>lennart@poettering.net</email>
  36                         </author>
  37                 </authorgroup>
  38         </refentryinfo>
  39
  40         <refmeta>
  41                 <refentrytitle>journalctl</refentrytitle>
  42                 <manvolnum>1</manvolnum>
  43         </refmeta>
  44
  45         <refnamediv>
  46                 <refname>journalctl</refname>
  47                 <refpurpose>Query the systemd journal</refpurpose>
  48         </refnamediv>
  49
  50         <refsynopsisdiv>
  51                 <cmdsynopsis>
  52                         <command>journalctl <arg choice="opt" rep="repeat">OPTIONS</arg> <arg choice="opt">MATCH</arg></command>
  53                 </cmdsynopsis>
  54         </refsynopsisdiv>
  55
  56         <refsect1>
  57                 <title>Description</title>
  58
  59                 <para><command>journalctl</command> may be
  60                 used to query the contents of the
  61                 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
  62                 journal.</para>
  63
  64                 <para>If called without parameter will show the full
  65                 contents of the journal, starting with the oldest
  66                 entry collected.</para>
  67
  68                 <para>If a match argument is passed the output is
  69                 filtered accordingly. A match is in the format
  70                 <literal>FIELD=VALUE</literal>,
  71                 e.g. <literal>_SYSTEMD_UNIT=httpd.service</literal>.</para>
  72
  73                 <para>Output is interleaved from all accessible
  74                 journal files, whether they are rotated or currently
  75                 being written, and regardless whether they belong to the
  76                 system itself or are accessible user journals.</para>
  77
  78                 <para>All users are granted access to their private
  79                 per-user journals. However, by default only root and
  80                 users who are members of the <literal>adm</literal>
  81                 group get access to the system journal and the
  82                 journals of other users.</para>
  83         </refsect1>
  84
  85         <refsect1>
  86                 <title>Options</title>
  87
  88                 <para>The following options are understood:</para>
  89
  90                 <variablelist>
  91                         <varlistentry>
  92                                 <term><option>--help</option></term>
  93                                 <term><option>-h</option></term>
  94
  95                                 <listitem><para>Prints a short help
  96                                 text and exits.</para></listitem>
  97                         </varlistentry>
  98
  99                         <varlistentry>
 100                                 <term><option>--version</option></term>
 101
 102                                 <listitem><para>Prints a short version
 103                                 string and exits.</para></listitem>
 104                         </varlistentry>
 105
 106                         <varlistentry>
 107                                 <term><option>--no-pager</option></term>
 108
 109                                 <listitem><para>Do not pipe output into a
 110                                 pager.</para></listitem>
 111                         </varlistentry>
 112
 113                         <varlistentry>
 114                                 <term><option>--all</option></term>
 115                                 <term><option>-a</option></term>
 116
 117                                 <listitem><para>Show all fields in
 118                                 full, even if they include unprintable
 119                                 characters or are very
 120                                 long.</para></listitem>
 121                         </varlistentry>
 122
 123                         <varlistentry>
 124                                 <term><option>--follow</option></term>
 125                                 <term><option>-f</option></term>
 126
 127                                 <listitem><para>Show only most recent
 128                                 journal entries, and continously print
 129                                 new entries as they are appended to
 130                                 the journal.</para></listitem>
 131                         </varlistentry>
 132
 133                         <varlistentry>
 134                                 <term><option>--lines=</option></term>
 135                                 <term><option>-n</option></term>
 136
 137                                 <listitem><para>Controls the number of
 138                                 journal lines to show, counting from
 139                                 the most recent ones. Takes a positive
 140                                 integer argument. In follow mode
 141                                 defaults to 10, otherwise is unset
 142                                 thus not limiting how many lines are
 143                                 shown.</para></listitem>
 144                         </varlistentry>
 145
 146                         <varlistentry>
 147                                 <term><option>--no-tail</option></term>
 148
 149                                 <listitem><para>Show all stored output
 150                                 lines, even in follow mode. Undoes the
 151                                 effect of
 152                                 <option>--lines=</option>.</para></listitem>
 153                         </varlistentry>
 154
 155                         <varlistentry>
 156                                 <term><option>--output=</option></term>
 157                                 <term><option>-o</option></term>
 158
 159                                 <listitem><para>Controls the
 160                                 formatting of the journal entries that are
 161                                 shown. Takes one of
 162                                 <literal>short</literal>,
 163                                 <literal>short-monotonic</literal>,
 164                                 <literal>verbose</literal>,
 165                                 <literal>export</literal>,
 166                                 <literal>json</literal>,
 167                                 <literal>cat</literal>. <literal>short</literal>
 168                                 is the default and generates an output
 169                                 that is mostly identical to the
 170                                 formatting of classic syslog log
 171                                 files, showing one line per journal
 172                                 entry. <literal>short-monotonic</literal>
 173                                 is very similar but shows monotonic
 174                                 timestamps instead of wallclock
 175                                 timestamps. <literal>verbose</literal>
 176                                 shows the full structered entry items
 177                                 with all
 178                                 fiels. <literal>export</literal>
 179                                 serializes the journal into a binary
 180                                 (but mostly text-based) stream
 181                                 suitable for backups and network
 182                                 transfer. <literal>json</literal>
 183                                 formats entries as JSON data
 184                                 structures. <literal>cat</literal>
 185                                 generates a very terse output only
 186                                 showing the actual message of each
 187                                 journal entry with no meta data, not
 188                                 even a timestamp.</para></listitem>
 189                         </varlistentry>
 190
 191                         <varlistentry>
 192                                 <term><option>--quiet</option></term>
 193                                 <term><option>-q</option></term>
 194
 195                                 <listitem><para>Suppresses any warning
 196                                 message regarding inaccessable system
 197                                 journals when run as normal
 198                                 user.</para></listitem>
 199                         </varlistentry>
 200
 201                         <varlistentry>
 202                                 <term><option>--local</option></term>
 203                                 <term><option>-l</option></term>
 204
 205                                 <listitem><para>Show only locally
 206                                 generated messages.</para></listitem>
 207                         </varlistentry>
 208
 209                         <varlistentry>
 210                                 <term><option>--new-id128</option></term>
 211
 212                                 <listitem><para>Instead of showing
 213                                 journal contents generate a new 128
 214                                 bit ID suitable for identifying
 215                                 messages. This is intended for usage
 216                                 by developers who need a new
 217                                 identifier for a new message they
 218                                 introduce and want to make
 219                                 recognizable. Will print the new ID in
 220                                 three different formats which can be
 221                                 copied into source code or
 222                                 similar.</para></listitem>
 223                         </varlistentry>
 224
 225                 </variablelist>
 226         </refsect1>
 227
 228         <refsect1>
 229                 <title>Exit status</title>
 230
 231                 <para>On success 0 is returned, a non-zero failure
 232                 code otherwise.</para>
 233         </refsect1>
 234
 235         <refsect1>
 236                 <title>Environment</title>
 237
 238                 <variablelist>
 239                         <varlistentry>
 240                                 <term><varname>$SYSTEMD_PAGER</varname></term>
 241                                 <listitem><para>Pager to use when
 242                                 <option>--no-pager</option> is not given;
 243                                 overrides <varname>$PAGER</varname>.  Setting
 244                                 this to an empty string or the value
 245                                 <literal>cat</literal> is equivalent to passing
 246                                 <option>--no-pager</option>.</para></listitem>
 247                         </varlistentry>
 248                 </variablelist>
 249         </refsect1>
 250
 251         <refsect1>
 252                 <title>See Also</title>
 253                 <para>
 254                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 255                         <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 256                         <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 257                 </para>
 258         </refsect1>
 259
 260 </refentry>