Kernighan and Pike's "The UNIX programming environment"[1] is still my favorite despite being old and certainly not up to date.<p>The book teaches the UNIX way of approaching problems with a set of simple tools that complement each other.<p>[1] <a href="http://cm.bell-labs.com/cm/cs/upe/" rel="nofollow">http://cm.bell-labs.com/cm/cs/upe/</a>