<para>If set to
<option>simple</option> (the default
- value if <varname>BusName=</varname>
- is not specified), it is expected that
- the process configured with
+ value if neither
+ <varname>Type=</varname> nor
+ <varname>BusName=</varname> are
+ specified), it is expected that the
+ process configured with
<varname>ExecStart=</varname> is the
main process of the service. In this
mode, if the process offers
<programlisting>ExecStart=/bin/sh -c 'dmesg | tac'
</programlisting>
- <para>Only select environment variables
+ <para>Only select environment variables that
are set for executed commands. See
<citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
</para>
considered successful termination, in
addition to the normal successful exit
code 0 and the signals <constant>SIGHUP</constant>, <constant>SIGINT</constant>,
- <constant>SIGTERM</constant> and <constant>SIGPIPE</constant>. Exit status
+ <constant>SIGTERM</constant>, and <constant>SIGPIPE</constant>. Exit status
definitions can either be numeric exit
codes or termination signal names,
- separated by spaces. Example:
- <literal>SuccessExitStatus=1 2 8
- <constant>SIGKILL</constant></literal>, ensures that exit
- codes 1, 2, 8 and the termination
- signal <constant>SIGKILL</constant> are considered clean
- service terminations. This option may
- appear more than once in which case
- the list of successful exit statuses
- is merged. If the empty string is
- assigned to this option, the list is
- reset, all prior assignments of this
- option will have no
- effect.</para></listitem>
+ separated by spaces. For example:
+ <programlisting>SuccessExitStatus=1 2 8 <constant>SIGKILL</constant></programlisting>
+ ensures that exit codes 1, 2, 8 and
+ the termination signal
+ <constant>SIGKILL</constant> are
+ considered clean service terminations.
+ </para>
+
+ <para>Note that if a process has a
+ signal handler installed and exits by
+ calling
+ <citerefentry><refentrytitle>_exit</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+ in response to a signal, the
+ information about the signal is lost.
+ Programs should instead perform cleanup and kill themselves with the same signal instead. See
+ <ulink url="http://www.cons.org/cracauer/sigint.html">Proper handling of SIGINT/SIGQUIT — How to be a proper program</ulink>.</para>
+
+ <para>This option may appear more than once
+ in which case the list of successful
+ exit statuses is merged. If the empty
+ string is assigned to this option, the
+ list is reset, all prior assignments
+ of this option will have no
+ effect.</para></listitem>
</varlistentry>
<varlistentry>