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:
-MacOS 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:
-MacOS X 10.5, AIX 5.2, HP-UX 11, IRIX 6.5, OSF/1 5.1, Solaris 11 2010-11.
+Mac OS X 10.5, AIX 5.2, HP-UX 11, IRIX 6.5, OSF/1 5.1, Solaris 11 2010-11.
@item
The function @code{getopt} does not obey the combination of @samp{+}
and @samp{:} flags in the options string on some platforms:
@item
The function @code{getopt} does not support options with optional arguments
on some platforms:
-MacOS X 10.5, OpenBSD 4.0, AIX 5.2, HP-UX 11, IRIX 6.5, OSF/1 5.1,
+Mac OS X 10.5, OpenBSD 4.0, AIX 5.2, HP-UX 11, IRIX 6.5, OSF/1 5.1,
Solaris 11 2010-11, Cygwin 1.5.x.
@item
The function @code{getopt_long} is missing on some platforms:
AIX 5.1, HP-UX 11, IRIX 6.5, OSF/1 5.1, Solaris 9, MSVC 9, Interix 3.5.
@item
+The function @code{getopt_long} does not support abbreviated long options
+where all disambiguations are equivalent on some platforms:
+OpenBSD 5.0.
+@item
The function @code{getopt_long_only} is missing on some platforms:
-MacOS X 10.3, FreeBSD 5.2.1, NetBSD 5.0, AIX 5.1, HP-UX 11, IRIX 6.5,
+Mac OS X 10.3, FreeBSD 5.2.1, NetBSD 5.0, AIX 5.1, HP-UX 11, IRIX 6.5,
OSF/1 5.1, Solaris 9, mingw, MSVC 9, Interix 3.5.
@item
This function crashes if the option string includes @code{W;} on some