You can do a lot with an empty file
<i>> Does this mean the smallest /bin/true is actually an empty file?</i><p>That was exactly the implementation of <i>/bin/true</i> in Unix v7: <<a href="https://github.com/v7unix/v7unix/blob/master/v7/bin/true" rel="nofollow">https://github.com/v7unix/v7unix/blob/master/v7/bin/true</a>>