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zsh_completion: Split out zsh _systemd-analyze
[elogind.git] / man / systemd-notify.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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8   Copyright 2010 Lennart Poettering
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22 -->
23
24 <refentry id="systemd-notify">
25
26         <refentryinfo>
27                 <title>systemd-notify</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>systemd-notify</refentrytitle>
42                 <manvolnum>1</manvolnum>
43         </refmeta>
44
45         <refnamediv>
46                 <refname>systemd-notify</refname>
47                 <refpurpose>Notify service manager about start-up completion and other daemon status changes</refpurpose>
48         </refnamediv>
49
50         <refsynopsisdiv>
51                 <cmdsynopsis>
52                         <command>systemd-notify <arg choice="opt" rep="repeat">OPTIONS</arg> <arg choice="opt" rep="repeat">VARIABLE=VALUE</arg></command>
53                 </cmdsynopsis>
54         </refsynopsisdiv>
55
56         <refsect1>
57                 <title>Description</title>
58
59                 <para><command>systemd-notify</command> may be
60                 called by daemon scripts to notify the init system
61                 about status changes. It can be used to send arbitrary
62                 information, encoded in an environment-block-like list
63                 of strings. Most importantly it can be used for
64                 start-up completion notification.</para>
65
66                 <para>This is mostly just a wrapper around
67                 <function>sd_notify()</function> and makes this
68                 functionality available to shell scripts. For details
69                 see
70                 <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para>
71
72                 <para>The command line may carry a list of
73                 environment variables to send as part of the status
74                 update.</para>
75
76                 <para>Note that systemd will refuse reception of
77                 status updates from this command unless
78                 <varname>NotifyAccess=all</varname> is set for the
79                 service unit this command is called from.</para>
80
81         </refsect1>
82
83         <refsect1>
84                 <title>Options</title>
85
86                 <para>The following options are understood:</para>
87
88                 <variablelist>
89                         <varlistentry>
90                                 <term><option>-h</option></term>
91                                 <term><option>--help</option></term>
92
93                                 <listitem><para>Prints a short help
94                                 text and exits.</para></listitem>
95                         </varlistentry>
96
97                         <varlistentry>
98                                 <term><option>--version</option></term>
99
100                                 <listitem><para>Prints a short version
101                                 string and exits.</para></listitem>
102                         </varlistentry>
103
104                         <varlistentry>
105                                 <term><option>--ready</option></term>
106
107                                 <listitem><para>Inform the init system
108                                 about service start-up
109                                 completion. This is equivalent to
110                                 <command>systemd-notify
111                                 READY=1</command>. For details about
112                                 the semantics of this option see
113                                 <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para></listitem>
114                         </varlistentry>
115
116                         <varlistentry>
117                                 <term><option>--pid=</option></term>
118
119                                 <listitem><para>Inform the init system
120                                 about the main PID of the
121                                 daemon. Takes a PID as argument. If
122                                 the argument is omitted the PID of the
123                                 process that invoked
124                                 <command>systemd-notify</command> is
125                                 used. This is equivalent to
126                                 <command>systemd-notify
127                                 MAINPID=$PID</command>. For details
128                                 about the semantics of this option see
129                                 <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para></listitem>
130                         </varlistentry>
131
132                         <varlistentry>
133                                 <term><option>--status=</option></term>
134
135                                 <listitem><para>Send a free-form
136                                 status string for the daemon to the
137                                 init systemd. This option takes the
138                                 status string as argument. This is
139                                 equivalent to <command>systemd-notify
140                                 STATUS=...</command>. For details
141                                 about the semantics of this option see
142                                 <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para></listitem>
143                         </varlistentry>
144
145                         <varlistentry>
146                                 <term><option>--booted</option></term>
147
148                                 <listitem><para>Returns 0 if the
149                                 system was booted up with systemd,
150                                 non-zero otherwise. If this option is
151                                 passed no message is sent. This option
152                                 is hence unrelated to the other
153                                 options. For details about the
154                                 semantics of this option see
155                                 <citerefentry><refentrytitle>sd_booted</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para></listitem>
156                         </varlistentry>
157
158                         <varlistentry>
159                                 <term><option>--readahead=</option></term>
160
161                                 <listitem><para>Controls disk
162                                 read-ahead operations. The argument
163                                 must be a string, and either "cancel",
164                                 "done" or "noreplay". For details
165                                 about the semantics of this option see
166                                 <citerefentry><refentrytitle>sd_readahead</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para></listitem>
167                         </varlistentry>
168                 </variablelist>
169
170         </refsect1>
171
172         <refsect1>
173                 <title>Exit status</title>
174
175                 <para>On success 0 is returned, a non-zero failure
176                 code otherwise.</para>
177         </refsect1>
178
179         <refsect1>
180                 <title>Example</title>
181
182                 <example>
183                         <title>Start-up Notification and Status Updates</title>
184
185                         <para>A simple shell daemon that sends
186                         start-up notifications after having set up its
187                         communication channel. During runtime it sends
188                         further status updates to the init
189                         system:</para>
190
191                         <programlisting>#!/bin/bash
192
193 mkfifo /tmp/waldo
194 systemd-notify --ready --status="Waiting for data..."
195
196 while : ; do
197         read a &lt; /tmp/waldo
198         systemd-notify --status="Processing $a"
199
200         # Do something with $a ...
201
202         systemd-notify --status="Waiting for data..."
203 done</programlisting>
204                 </example>
205         </refsect1>
206
207         <refsect1>
208                 <title>See Also</title>
209                 <para>
210                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
211                         <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
212                         <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
213                         <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
214                         <citerefentry><refentrytitle>sd_booted</refentrytitle><manvolnum>3</manvolnum></citerefentry>
215                 </para>
216         </refsect1>
217
218 </refentry>