- specified more than once. Optionally,
- if the absolute file name is prefixed
- with @, the second token will be
- passed as argv[0] to the executed
- process, followed by the further
- arguments specified. Unless
- <option>Type=forking</option> is set,
- the process started via this command
- line will be considered the main
- process of the
- daemon.</para></listitem>
+ 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
+ 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
+ abnormal 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 precede
+ 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>.</para>
+
+ <para>On top of that basic environment
+ variable substitution is
+ supported. Use
+ <literal>${FOO}</literal> as part of a
+ word, or as word of its own on the
+ command line, in which case it will be
+ replaced by the value of the
+ environment variable including all
+ whitespace it contains, resulting in a
+ single argument. Use
+ <literal>$FOO</literal> as a separate
+ word on the command line, in which
+ case it will be replaced by the value
+ of the environment variable split up
+ at whitespace, resulting in no or more
+ arguments. Note that the first
+ argument (i.e. the program to execute)
+ may not be a variable, and must be a
+ literal and absolute path
+ name.</para></listitem>