Portability problems fixed by either Gnulib module @code{getopt-posix} or @code{getopt-gnu}:
@itemize
@item
-The @code{getopt} function keeps some internal state that cannot be explicitly
-reset on some platforms:
-mingw.
+This function is missing on some platforms:
+MSVC 9.
@item
The value of @code{optind} after a missing required argument is wrong
on some platforms:
-Mac OS X 10.5, AIX 7.1.
+Mac OS X 10.5, AIX 7.1, mingw.
@end itemize
Portability problems fixed by Gnulib module @code{getopt-gnu}:
@itemize
@item
-This function is missing on some platforms:
-MSVC 9.
-@item
The function @code{getopt} does not support the @samp{+} flag in the options
string on some platforms:
Mac OS X 10.5, AIX 5.2, HP-UX 11, IRIX 6.5, OSF/1 5.1, Solaris 11 2010-11.