As Jonathan Wakely wrote: > POSIX diff with the -b option should report the files as equal, I > don't know if that's portable enough to rely on though.
I think it is. The Single Unix Specification requires the -b option ("Cause any amount of white space at the end of a line to be treated as a single <newline>"), and the exit status 0 for "no differences found", 1 for "differences found", and > 1 for "an error occurred" are also standardized. I don't know of any (even historic) diff that doesn't provide -b. There's no option to suppress printing the differences to stdout though, and redirecting the output to a null device is likely not portable. I don't know whether this situation already applies to other GCC Makefiles, but perhaps the most portable way for this is to redirect stdout to a dummy file, and delete that file afterwards. -- cheers, J"org .-.-. --... ...-- -.. . DL8DTL http://www.sax.de/~joerg/ NIC: JW11-RIPE Never trust an operating system you don't have sources for. ;-)