Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!ucbvax!decwrl!decvax!ima!haddock!karl
From: karl@haddock.ima.isc.com (Karl Heuer)
Newsgroups: comp.lang.c
Subject: Re: getopt
Message-ID: <13730@haddock.ima.isc.com>
Date: 16 Jun 89 02:29:01 GMT
References: <782@crdgw1.crd.ge.com>
Reply-To: karl@haddock.ima.isc.com (Karl Heuer)
Organization: Interactive Systems, Boston
Lines: 27

In article <782@crdgw1.crd.ge.com> davidsen@crdos1.UUCP (bill davidsen) writes:
>I have a program which needs an option which may have either a default
>value or a specific value. ie. "-c" or "-c4" would be typical. I would
>like to use getopt to read the values.

This doesn't fit the Official Arg Passing Style, so even if you use a hook a
kludge into getopt(), it isn't guaranteed to always work.

>  In the meantime, I took a P.D. version and added another option
>qualifier, #, indicating an optional numeric argument.

Why restrict it to numeric?  I use optional non-numeric arguments all the
time.  If you're going to add the optional-argument hack, you might as well
let it return (in optarg) whatever string immediately followed the keyletter,
including the empty string in the case of "-c".  (No reason for it ever to
return NULL; that would make an unnecessary special case.)

>Since the character # could be an option in some software, my new version is
>not a superset.

"-#" is a not uncommon debugging option.  I think ";" is a better choice,
since it does half of what ":" does%, and because I don't know of any code
that uses "-;" as an option.

Karl W. Z. Heuer (ima!haddock!karl or karl@haddock.isc.com), The Walking Lint
________
% This pun works only if you pronounce them as "semicolon" and "colon".