eudev/man/systemd-notify.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="systemd-notify">
<refentryinfo>
<title>systemd-notify</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-notify</refentrytitle>
<manvolnum>1</manvolnum>
</refmeta>
<refnamediv>
<refname>systemd-notify</refname>
<refpurpose>Notify init system about start-up completion and other daemon status changes</refpurpose>
</refnamediv>
<refsynopsisdiv>
<cmdsynopsis>
<command>systemd-notify <arg choice="opt" rep="repeat">OPTIONS</arg> <arg choice="opt" rep="repeat">VARIABLE=VALUE</arg></command>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para><command>systemd-notify</command> may be
called by daemon scripts to notify the init system
about status changes. It can be used to send arbitrary
information, encoded in an environment-block-like list
of strings. Most importantly it can be used for
start-up completion notification.</para>
<para>This is mostly just a wrapper around
<function>sd_notify()</function> and makes this
functionality available to shell scripts. For details
see
<citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para>
<para>The command line may carry a list of
environment variables to send as part of the status
update.</para>
<para>Note that systemd will refuse reception of
status updates from this command unless
<varname>NotifyAccess=all</varname> is set for the
service unit this command is called from.</para>
</refsect1>
<refsect1>
<title>Options</title>
<para>The following options are understood:</para>
<variablelist>
<varlistentry>
<term><option>--h</option></term>
<term><option>--help</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>--ready</option></term>
<listitem><para>Inform the init system
about service start-up
completion. This is equivalent to
<command>systemd-notify
READY=1</command>. For details about
the semantics of this option see
<citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--pid=</option></term>
<listitem><para>Inform the init system
about the main PID of the
daemon. Takes a PID as argument. If
the argument is omitted the PID of the
process that invoked
<command>systemd-notify</command> is
used. This is equivalent to
<command>systemd-notify
MAINPID=$PID</command>. For details
about the semantics of this option see
<citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--status=</option></term>
<listitem><para>Send a free-form
status string for the daemon to the
init systemd. This option takes the
status string as argument. This is
equivalent to <command>systemd-notify
STATUS=...</command>. For details
about the semantics of this option see
<citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--booted</option></term>
<listitem><para>Returns 0 if the
system was booted up with systemd,
non-zero otherwise. If this option is
passed no message is sent. This option
is hence unrelated to the other
options. For details about the
semantics of this option see
<citerefentry><refentrytitle>sd_booted</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--readahead=</option></term>
<listitem><para>Controls disk
read-ahead operations. The argument
must be a string, and either "cancel",
"done" or "noreplay". For details
about the semantics of this option see
<citerefentry><refentrytitle>sd_readahead</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</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>Example</title>
<example>
<title>Start-up Notification and Status Updates</title>
<para>A simple shell daemon that sends
start-up notifications after having set up its
communication channel. During runtime it sends
further status updates to the init
system:</para>
<programlisting>#!/bin/bash
mkfifo /tmp/waldo
systemd-notify --ready --status="Waiting for data..."
while : ; do
read a &lt; /tmp/waldo
systemd-notify --status="Processing $a"
# Do something with $a ...
systemd-notify --status="Waiting for data..."
done</programlisting>
</example>
</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.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd_booted</refentrytitle><manvolnum>3</manvolnum></citerefentry>
</para>
</refsect1>
</refentry>