[PATCH] getopt,argp - reentrant getopt interface, argp fixes

[Roland McGrath]

> Then the interface is misused this way.  getopt explicitly is not thread
> safe in POSIX because of its restricted use.

We are talking about argp here, really.  I hope you won't claim such uses
were not part of the original intent of argp, because they most certainly
were.  The reason for changing getopt is to make it a suitable subroutine
for a cleaned-up argp.  The other alternatives are to make such new entry
points wholly internal, just to be used by argp, or rewrite argp not to use
getopt at all.  The latter I think is a bad idea because it is prone to
errors arising in the form of divergence between getopt and argp vis a vis
command line syntax details, as well as just being undesireable duplication
of code.