Well, step one is to find out if pianobar gets upset because its standard output is not a TTY. So change "llib pianobar" to be "llib pianobar | grep -v "|>" and see if it still runs OK.

If it doesn't, then probably it would be better to modify pianobar to do the initial setup itself. Yes, that means modifying the app, but this sounds like a reasonable enhancement (setting initial volume).

FWIW, it might be easier to grep -v the cruft after you grab the song list. Then it won't interfere with the app's TTY access, and you don't have to hack C code either. :->

Andy