Is this not part of POSIX? I see folks churning about Go and the Bell Labs people, but these styles were exactly what (in my mind) POSIX was partially in response to.
OpenBSD, just as one example of a true unix-derived system, added it's own getopt_long only in 3.3 release which was 2003, ~17 years after the 1st posix in 1988. This article mentions getopt_long originating ~1990, after 1st posix standard.
