{stdenv, fetchurl}:

stdenv.mkDerivation {
  name = "pcre-7.1";
  src = fetchurl {
    url = ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/pcre-7.1.tar.bz2;
    sha256 = "0rpkcw07jas3fw6ava3ni5zcrmbncwa8xlsa0lzq6z2iph5510li";
  };
}