Here's a list of things left to do in no particular order:

* I don't like the regexp syntax (can be very cryptic),
  but it feels like the old_str original string should allow it
  (and maybe with the -x option too).

* ftw() isn't very portable outside of the UNIX environment - probably need
  to reccode the recursion to avoid using it. replace might eventually then
  compile OK with Cygwin...

* Handle printf()-style escape sequences (particularly \r and \n) so that
  you can replace carriage returns/line feeds easily in text files
  (Windows naff text file format strikes again...).

* A replace.spec RPM config file would be nice, plus Makefile rules to
  build a binary RPM (initially Fedora Core 2, maybe others later).