/^#undef DIRECTORY_SEP *$/s!^.*$!#define DIRECTORY_SEP '/'!
/^#undef DOS_NT *$/s/^.*$/#define DOS_NT/
/^#undef FLOAT_CHECK_DOMAIN *$/s/^.*$/#define FLOAT_CHECK_DOMAIN/
/^#undef DIRECTORY_SEP *$/s!^.*$!#define DIRECTORY_SEP '/'!
/^#undef DOS_NT *$/s/^.*$/#define DOS_NT/
/^#undef FLOAT_CHECK_DOMAIN *$/s/^.*$/#define FLOAT_CHECK_DOMAIN/