One of my pastimes is randomly exploring the Unix Toolkit. It's basically, "What is this thing? What does it do? Do I have a use for it?" And even if the answer

One of my pastimes is randomly exploring the Unix Toolkit. It's basically, "What is this thing? What does it do? Do I have a use for it?" And even if the answer is "no", at least I now know it exists and where to find it should my needs change...