I am thinking of learning how to program. Given that the built-in Basic for the Apple IIc is a bit out of style, anyone have any advice on what language I should learn? My criteria are:

1) There should be a free compiler/interpreter that will run on my iBook (OSX or X11 is fine).

2) I only want to read one book. So there should be a good book which can serve both as a reference and as instruction.

3) I want to be able to make calls to grep from inside programs.

4) I want to be able to manipulate wordlists with relative ease (say, replace all a's with x's, or make a new wordlist consisting of concatenations of all pairs of words from the old wordlist, etc.).

5) Aesthetically I tend to prefer recursion to iteration.