I have a podcast that downloads as multiple segments over multiple days. Its format arrives as YYYYMMDD_showcode_segment.mp3; so, for example, one download might result in files as 20090323_goofa_01.mp3 through 20090323_goofa_21.mp3, and also within the same download 20090324_goofa_01.mp3 through 20090324_goofa_21.mp3. What I'm looking for is a Unix script (shell, perl, what have you) that would look at a directory and look at what dates are represented there, and let me join all of the segments together by day. I can use mpgtx -j to do the actual joining; I'm looking for the code that would let the script determine what dates are in the directory and then get each day's segments united into a single MP3 for that day's show.
Faster techniques for grabbing lines of a file and doing text manipulation and arithmetic via shell (or other) scripting? [more inside]