chiark / gitweb /
systemctl: skip writing of utmp if we booted using systemd, under the assumption...
[elogind.git] / man / systemd.service.xml
index 7eaf9cbce3a316dc604bfde2e23ce96b3755403f..c3eebeabc1950395f31b1f03340dbe846c25fe9c 100644 (file)
                                 start-up type for this service
                                 unit. One of <option>simple</option>,
                                 <option>forking</option>,
                                 start-up type for this service
                                 unit. One of <option>simple</option>,
                                 <option>forking</option>,
-                                <option>finish</option>,
+                                <option>oneshot</option>,
                                 <option>dbus</option>,
                                 <option>notify</option>.</para>
 
                                 <option>dbus</option>,
                                 <option>notify</option>.</para>
 
                                 configured with
                                 <varname>ExecStart=</varname> is the
                                 main process of the service. In this
                                 configured with
                                 <varname>ExecStart=</varname> is the
                                 main process of the service. In this
-                                mode, communication channels must be
-                                installed before the daemon is started
-                                up (e.g. sockets set up by systemd,
-                                via socket activation), as systemd
-                                will immediately proceed starting
-                                follow-up units.</para>
+                                mode, if the process offers
+                                functionality to other processes on
+                                the system its communication channels
+                                should be installed before the daemon
+                                is started up (e.g. sockets set up by
+                                systemd, via socket activation), as
+                                systemd will immediately proceed
+                                starting follow-up units.</para>
 
                                 <para>If set to
                                 <option>forking</option> it is
                                 expected that the process configured
                                 with <varname>ExecStart=</varname>
 
                                 <para>If set to
                                 <option>forking</option> it is
                                 expected that the process configured
                                 with <varname>ExecStart=</varname>
-                                will start up and call
-                                <function>fork()</function>. The
-                                parent process is expected to finish
-                                when start-up is complete and all
-                                communication channels set up. The
-                                child continues to run as the main
-                                daemon process. This is the behaviour
-                                of traditional UNIX daemons. If this
+                                will call <function>fork()</function>
+                                as part of its start-up. The parent process is
+                                expected to exit when start-up is
+                                complete and all communication
+                                channels set up. The child continues
+                                to run as the main daemon
+                                process. This is the behaviour of
+                                traditional UNIX daemons. If this
                                 setting is used, it is recommended to
                                 also use the
                                 <varname>PIDFile=</varname> option, so
                                 setting is used, it is recommended to
                                 also use the
                                 <varname>PIDFile=</varname> option, so
                                 exits.</para>
 
                                 <para>Behaviour of
                                 exits.</para>
 
                                 <para>Behaviour of
-                                <option>finish</option> is similar
+                                <option>oneshot</option> is similar
                                 to <option>simple</option>, however
                                 it is expected that the process has to
                                 exit before systemd starts follow-up
                                 to <option>simple</option>, however
                                 it is expected that the process has to
                                 exit before systemd starts follow-up
                                 will proceed starting follow-up units
                                 after the D-Bus bus name has been
                                 acquired. Service units with this
                                 will proceed starting follow-up units
                                 after the D-Bus bus name has been
                                 acquired. Service units with this
-                                option configured implicitly have
+                                option configured implicitly gain
                                 dependencies on the
                                 <filename>dbus.target</filename>
                                 unit.</para>
                                 dependencies on the
                                 <filename>dbus.target</filename>
                                 unit.</para>
                                 notification message has been sent. If
                                 this option is used
                                 <varname>NotifyAccess=</varname> (see
                                 notification message has been sent. If
                                 this option is used
                                 <varname>NotifyAccess=</varname> (see
-                                below) must be set to open access to
+                                below) should be set to open access to
                                 the notification socket provided by
                                 systemd. If
                                 <varname>NotifyAccess=</varname> is not
                                 the notification socket provided by
                                 systemd. If
                                 <varname>NotifyAccess=</varname> is not
-                                set, it will be implicitly set to
+                                set, it will implicitly be set to
                                 <option>main</option>.</para>
                                 </listitem>
                         </varlistentry>
                                 <option>main</option>.</para>
                                 </listitem>
                         </varlistentry>
                                 arguments for the process. It is
                                 mandatory to set this option for all
                                 services. This option may not be
                                 arguments for the process. It is
                                 mandatory to set this option for all
                                 services. This option may not be
-                                specified more than once. Optionally,
-                                if the absolute file name is prefixed
-                                with <literal>@</literal>, the second
-                                token will be passed as
+                                specified more than once, except when
+                                <varname>Type=oneshot</varname> is
+                                used in which case more than one
+                                <varname>ExecStart=</varname> line is
+                                accepted which are then invoked one by
+                                one, sequentially in the order they
+                                appear in the unit file.</para>
+
+                                <para>Optionally, if the absolute file
+                                name is prefixed with
+                                <literal>@</literal>, the second token
+                                will be passed as
                                 <literal>argv[0]</literal> to the
                                 executed process, followed by the
                                 <literal>argv[0]</literal> to the
                                 executed process, followed by the
-                                further arguments specified. Unless
-                                <varname>Type=forking</varname> is set,
-                                the process started via this command
-                                line will be considered the main
-                                process of the
-                                daemon.</para></listitem>
+                                further arguments specified. If the
+                                first token is prefixed with
+                                <literal>-</literal> an exit code of
+                                the command normally considered a
+                                failure (i.e. non-zero exit status or
+                                abormal exit due to signal) is ignored
+                                and considered success. If both
+                                <literal>-</literal> and
+                                <literal>@</literal> are used for the
+                                same command the former must preceed
+                                the latter. Unless
+                                <varname>Type=forking</varname> is
+                                set, the process started via this
+                                command line will be considered the
+                                main process of the daemon. The
+                                command line accepts % specifiers as
+                                described in
+                                <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. On
+                                top of that basic environment variable
+                                substitution is supported, where
+                                <literal>${FOO}</literal> is replaced
+                                by the string value of the environment
+                                variable of the same name. Also
+                                <literal>$FOO</literal> may appear as
+                                seperate word on the command line in
+                                which case the variable is replaced by
+                                its value split at
+                                whitespaces.</para></listitem>
                         </varlistentry>
 
                         <varlistentry>
                         </varlistentry>
 
                         <varlistentry>
                                 suitable for XDG
                                 <filename>.desktop</filename> files.
                                 Use of these settings is
                                 suitable for XDG
                                 <filename>.desktop</filename> files.
                                 Use of these settings is
-                                optional.</para></listitem>
+                                optional. Specifier and environment
+                                variable substitution is
+                                supported.</para></listitem>
                         </varlistentry>
 
                         <varlistentry>
                         </varlistentry>
 
                         <varlistentry>
                                 scheme as pointed out for
                                 <varname>ExecStartPre=</varname>
                                 above. Use of this setting is
                                 scheme as pointed out for
                                 <varname>ExecStartPre=</varname>
                                 above. Use of this setting is
-                                optional.  </para></listitem>
+                                optional. Specifier and environment
+                                variable substitution is supported
+                                here following the same scheme as for
+                                <varname>ExecStart=</varname>. One
+                                special environment variable is set:
+                                if known <literal>$MAINPID</literal> is
+                                set to the main process of the
+                                daemon, and may be used for command
+                                lines like the following:
+                                <command>/bin/kill -HUP
+                                $(MAINPID)</command>.</para></listitem>
                         </varlistentry>
 
                         <varlistentry>
                         </varlistentry>
 
                         <varlistentry>
                                 (see below). If this option is not
                                 specified the process is terminated
                                 right-away when service stop is
                                 (see below). If this option is not
                                 specified the process is terminated
                                 right-away when service stop is
-                                requested.</para></listitem>
+                                requested. Specifier and environment
+                                variable substitution is supported
+                                (including
+                                <literal>$(MAINPID)</literal>, see
+                                above).</para></listitem>
                         </varlistentry>
 
                         <varlistentry>
                         </varlistentry>
 
                         <varlistentry>
                                 out for
                                 <varname>ExecStartPre</varname>. Use
                                 of these settings is
                                 out for
                                 <varname>ExecStartPre</varname>. Use
                                 of these settings is
-                                optional.</para></listitem>
+                                optional. Specifier and environment
+                                variable substitution is
+                                supported.</para></listitem>
                         </varlistentry>
 
                         <varlistentry>
                         </varlistentry>
 
                         <varlistentry>