systemd/man/journalctl.xml
Lennart Poettering 5430f7f2bc relicense to LGPLv2.1 (with exceptions)
We finally got the OK from all contributors with non-trivial commits to
relicense systemd from GPL2+ to LGPL2.1+.

Some udev bits continue to be GPL2+ for now, but we are looking into
relicensing them too, to allow free copy/paste of all code within
systemd.

The bits that used to be MIT continue to be MIT.

The big benefit of the relicensing is that closed source code may now
link against libsystemd-login.so and friends.
2012-04-12 00:24:39 +02:00

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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">
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<refentry id="journalctl">
<refentryinfo>
<title>journalctl</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>journalctl</refentrytitle>
<manvolnum>1</manvolnum>
</refmeta>
<refnamediv>
<refname>journalctl</refname>
<refpurpose>Query the systemd journal</refpurpose>
</refnamediv>
<refsynopsisdiv>
<cmdsynopsis>
<command>journalctl <arg choice="opt" rep="repeat">OPTIONS</arg> <arg choice="opt">MATCH</arg></command>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para><command>journalctl</command> may be
used to query the contents of the
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
journal.</para>
<para>If called without parameter will show the full
contents of the journal, starting with the oldest
entry collected.</para>
<para>If a match argument is passed the output is
filtered accordingly. A match is in the format
<literal>FIELD=VALUE</literal>,
e.g. <literal>_SYSTEMD_UNIT=httpd.service</literal>. See
<citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>
for a list of well-known fields.</para>
<para>Output is interleaved from all accessible
journal files, whether they are rotated or currently
being written, and regardless whether they belong to the
system itself or are accessible user journals.</para>
<para>All users are granted access to their private
per-user journals. However, by default only root and
users who are members of the <literal>adm</literal>
group get access to the system journal and the
journals of other users.</para>
</refsect1>
<refsect1>
<title>Options</title>
<para>The following options are understood:</para>
<variablelist>
<varlistentry>
<term><option>--help</option></term>
<term><option>-h</option></term>
<listitem><para>Prints a short help
text and exits.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--version</option></term>
<listitem><para>Prints a short version
string and exits.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--no-pager</option></term>
<listitem><para>Do not pipe output into a
pager.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--all</option></term>
<term><option>-a</option></term>
<listitem><para>Show all fields in
full, even if they include unprintable
characters or are very
long.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--follow</option></term>
<term><option>-f</option></term>
<listitem><para>Show only most recent
journal entries, and continously print
new entries as they are appended to
the journal.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--lines=</option></term>
<term><option>-n</option></term>
<listitem><para>Controls the number of
journal lines to show, counting from
the most recent ones. Takes a positive
integer argument. In follow mode
defaults to 10, otherwise is unset
thus not limiting how many lines are
shown.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--no-tail</option></term>
<listitem><para>Show all stored output
lines, even in follow mode. Undoes the
effect of
<option>--lines=</option>.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--output=</option></term>
<term><option>-o</option></term>
<listitem><para>Controls the
formatting of the journal entries that are
shown. Takes one of
<literal>short</literal>,
<literal>short-monotonic</literal>,
<literal>verbose</literal>,
<literal>export</literal>,
<literal>json</literal>,
<literal>cat</literal>. <literal>short</literal>
is the default and generates an output
that is mostly identical to the
formatting of classic syslog log
files, showing one line per journal
entry. <literal>short-monotonic</literal>
is very similar but shows monotonic
timestamps instead of wallclock
timestamps. <literal>verbose</literal>
shows the full structered entry items
with all
fiels. <literal>export</literal>
serializes the journal into a binary
(but mostly text-based) stream
suitable for backups and network
transfer. <literal>json</literal>
formats entries as JSON data
structures. <literal>cat</literal>
generates a very terse output only
showing the actual message of each
journal entry with no meta data, not
even a timestamp.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--quiet</option></term>
<term><option>-q</option></term>
<listitem><para>Suppresses any warning
message regarding inaccessable system
journals when run as normal
user.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--local</option></term>
<term><option>-l</option></term>
<listitem><para>Show only locally
generated messages.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--new-id128</option></term>
<listitem><para>Instead of showing
journal contents generate a new 128
bit ID suitable for identifying
messages. This is intended for usage
by developers who need a new
identifier for a new message they
introduce and want to make
recognizable. Will print the new ID in
three different formats which can be
copied into source code or
similar.</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>Environment</title>
<variablelist>
<varlistentry>
<term><varname>$SYSTEMD_PAGER</varname></term>
<listitem><para>Pager to use when
<option>--no-pager</option> is not given;
overrides <varname>$PAGER</varname>. Setting
this to an empty string or the value
<literal>cat</literal> is equivalent to passing
<option>--no-pager</option>.</para></listitem>
</varlistentry>
</variablelist>
</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>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
<citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
</para>
</refsect1>
</refentry>