described the -u option

git-svn-id: svn://bind10.isc.org/svn/bind10/branches/trac268@2572 e5f2f494-b856-4b98-b285-d166d9295462

src/bin/auth/b10-auth.xml

@@ -48,6 +48,7 @@
       <arg><option>-4</option></arg>
       <arg><option>-6</option></arg>
       <arg><option>-p <replaceable>number</replaceable></option></arg>
+      <arg><option>-u <replaceable>username</replaceable></option></arg>
       <arg><option>-v</option></arg>
     </cmdsynopsis>
   </refsynopsisdiv>
@@ -120,6 +121,20 @@
       </varlistentry>
 
       <varlistentry>
+        <term><option>-u <replaceable>username</replaceable></option></term>
+        <listitem>
+	  <para>
+	    The user name of the <command>b10-auth</command> daemon.
+	    If specified, the daemon changes the process owner to the
+	    specified user.
+	    The <replaceable>username</replaceable> must be either a
+	    valid numeric user ID or a valid user name.
+	    By default the daemon runs as the user who invokes it.
+	  </para>
+        </listitem>
+      </varlistentry>
+
+      <varlistentry>
         <term><option>-v</option></term>
         <listitem><para>
           Enabled verbose mode. This enables diagnostic messages to