What's the one Linux command you wish you knew years ago?
For me it was definitely find. I went through a ton of contortions to replicate its behavior several times before somebody knowledgeable clued me in.<p>Also, `` and $(). Find combined with one of these is great. One of my favorite one-liners (I even figured it out myself :)) is:<p><pre><code>    cat `find . --name *.java` | wc -l</code></pre>