source: branches/samba-3.3.x/docs-xml/smbdotconf/logon/shutdownscript.xml

<samba:parameter name="shutdown script"
                 context="G"
                                 type="string"
                 advanced="1" developer="1"
                 xmlns:samba="http://www.samba.org/samba/DTD/samba-doc">
<description>
        <para>This a full path name to a script called by 
         <citerefentry><refentrytitle>smbd</refentrytitle> 
        <manvolnum>8</manvolnum></citerefentry> that should 
        start a shutdown procedure.</para>

        <para>If the connected user posseses the <constant>SeRemoteShutdownPrivilege</constant>,
        right, this command will be run as root.</para>

        <para>The %z %t %r %f variables are expanded as follows:</para>
        
        <itemizedlist>
                <listitem>
                        <para><parameter moreinfo="none">%z</parameter> will be substituted with the
                        shutdown message sent to the server.</para>
                </listitem>
                
                <listitem>
                        <para><parameter moreinfo="none">%t</parameter> will be substituted with the
                        number of seconds to wait before effectively starting the
                        shutdown procedure.</para>
                </listitem>
                
                <listitem>
                        <para><parameter moreinfo="none">%r</parameter> will be substituted with the
                        switch <emphasis>-r</emphasis>. It means reboot after shutdown
                        for NT.</para>
                </listitem>
                
                <listitem>
                        <para><parameter moreinfo="none">%f</parameter> will be substituted with the
                        switch <emphasis>-f</emphasis>. It means force the shutdown
                        even if applications do not respond for NT.</para>
                </listitem>
        </itemizedlist>

        <para>Shutdown script example:
<programlisting format="linespecific">
#!/bin/bash

time=$2
let time=&quot;${time} / 60&quot;
let time=&quot;${time} + 1&quot;

/sbin/shutdown $3 $4 +$time $1 &amp;

</programlisting>
        Shutdown does not return so we need to launch it in background.
        </para>

</description>
<related>abort shutdown script</related>
<value type="default"></value>
<value type="example">/usr/local/samba/sbin/shutdown %m %t %r %f</value>

</samba:parameter>