<code>r</code>
     <dd>Remove a trailing suffix of the form <code>.</code><var>suffix</var><code></code>, leaving
the basename.

     <br><dt><code>e</code>
     <dd>Remove all but the trailing suffix.

     <br><dt><code>p</code>
     <dd>Print the new command but do not execute it.

     <br><dt><code>s/</code><var>old</var><code>/</code><var>new</var><code>/</code>
     <dd>Substitute <var>new</var> for the first occurrence of <var>old</var> in the
event line.  Any delimiter may be used in place of <cod