
This is required on OS X and other systems which do not have the glibc extensions for regular expressions (FreeBSD is not one of them as it already includes gnuregex in /usr). With this there are no hardcoded non-standard paths for OS X anymore. regex.c and regex.h are from the official gnuregex 0.12 distribution, the only modification is that I added __BEGIN_DECLS and __END_DECLS to regex.h.