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Diffstat (limited to 'man/systemd.service.xml')
| -rw-r--r-- | man/systemd.service.xml | 97 |
1 files changed, 80 insertions, 17 deletions
diff --git a/man/systemd.service.xml b/man/systemd.service.xml index 22c0d5ae9f..103c495fbe 100644 --- a/man/systemd.service.xml +++ b/man/systemd.service.xml @@ -305,9 +305,10 @@ <term><varname>ExecStart=</varname></term> <listitem><para>Commands with their arguments that are executed when this - service is started. The first - argument must be an absolute path - name.</para> + service is started. For each of the + specified commands, the first argument + must be an absolute and literal path + to an executable.</para> <para>When <varname>Type</varname> is not <option>oneshot</option>, only one @@ -332,6 +333,35 @@ prior assignments of this option will have no effect.</para> + <para>Each command line is split on + whitespace, with the first item being + the command to execute, and the + subsequent items being the arguments. + Double quotes ("...") and single + quotes ('...') may be used, in which + case everything until the next + matching quote becomes part of the + same argument. Quotes themselves are + removed after parsing. In addition, a + trailing backslash + (<literal>\</literal>) may be used to + merge lines. This syntax is intended + to be very similar to shell syntax, + but only the meta-characters and + expansions described in the following + paragraphs are understood. + Specifically, redirection using + <literal><</literal>, + <literal><<</literal>, + <literal>></literal>, and + <literal>>></literal>, pipes + using <literal>|</literal>, and + running programs in the background + using <literal>&</literal> + and <emphasis>other elements of shell + syntax are not supported</emphasis>. + </para> + <para>If more than one command is specified, the commands are invoked one by one sequentially in the order @@ -350,10 +380,11 @@ <para>The command line accepts <literal>%</literal> specifiers as described in - <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. Note - that the first argument of the command - line (i.e. the program to execute) may - not include specifiers.</para> + <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. + Note that the first argument of the + command line (i.e. the program to + execute) may not include + specifiers.</para> <para>Basic environment variable substitution is supported. Use @@ -372,9 +403,7 @@ more arguments. To pass a literal dollar sign, use <literal>$$</literal>. Note that the first argument (i.e. the program to execute) - may not be a variable, since it must - be a literal and absolute path - name.</para> + may not be a variable.</para> <para>Optionally, if the absolute file name is prefixed with @@ -402,13 +431,47 @@ <programlisting>ExecStart=/bin/sh -c 'dmesg | tac' </programlisting> - <para>For services run by a user - instance of systemd the special - environment variable - <varname>$MANAGERPID</varname> is set - to the PID of the systemd - instance.</para> - </listitem> + <para>Only select environment variables + are set for executed commands. See + <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>. + </para> + + <para>Example:</para> + <programlisting>ExecStart=/bin/echo one ; /bin/echo "two two" + </programlisting> + <para>This will execute + <command>/bin/echo</command> two + times, each time with one argument, + <literal>one</literal> and + <literal>two two</literal>, + respectively. Since two commands are + specified + <varname>Type=oneshot</varname> must + be used.</para> + + <para>Example:</para> + <programlisting>ExecStart=/bin/echo / >/dev/null & \; \ +/bin/ls + </programlisting> + <para>This will execute + <command>/bin/echo</command> with five + arguments: <literal>/</literal>, + <literal>>/dev/null</literal>, + <literal>&</literal>, + <literal>;</literal>, and + <literal>/bin/ls</literal>.</para> + + <para>Example:</para> + <programlisting>Environment="ONE=one" 'TWO=two two' +ExecStart=/bin/echo $ONE $TWO ${TWO} + </programlisting> + <para>This will execute + <command>/bin/echo</command> with four + arguments: <literal>one</literal>, + <literal>two</literal>, + <literal>two</literal>, and + <literal>two two</literal>.</para> + </listitem> </varlistentry> <varlistentry> |