&gt; The &quot;UNIX philosophy&quot; is good, it&#x27;s just that UNIX doesn&#x27;t really follow it.<p>It never did, beyond some examples in beginner books.<p>&gt; Look at `cat` for example. It might as well be `str + str...`. Or look at `grep`, it&#x27;s basically `filter` or `reduce` at heart.<p>Then look at the options of `cat`. On my Linux system cat has a -n option, which numbers the output lines. If it were following the &#x27;UNIX philosophy&#x27;, this option would not exist.