It is irrelevant how it is implemented. The command means "compare the output of those two commands" and the only correct result is "they differ on byte 5". It is clearly a bug. -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple