Having developed code in C for fifteen years before discovering awk and then Perl, I know that for anything to do with file manipulation I'd use Perl, hands down. I can remember writing C utilities many times, writing argument parsing and file manipulation routines over and over again, thinking to myself, "This is stupid -- I haven't even got to the part that I want to do yet!"

Don't get me wrong -- C is an awesome language, and it's blazingly fast; but it's a bit like building a house using individual 2x4s rather than the pre-built Walls that Perl provides. :)