Re: [ALTERNATE PATCH] Add a simple option parser.

From: David Kastrup <dak@gnu.org>
Date: Oct 5, 2007, 14:59 UTC
Message-ID: <86lkahwqsz.fsf@lola.quinscape.zz>
In-Reply-To: <20071005143014.GA18176@glandium.org>

Mike Hommey <mh@glandium.org> writes:

Show 14 quoted lines

> On Fri, Oct 05, 2007 at 04:25:07PM +0200, Pierre Habouzit <madcoder@debian.org> wrote:
>> The option parser takes argc, argv, an array of struct option
>> and a usage string.  Each of the struct option elements in the array
>> describes a valid option, its type and a pointer to the location where the
>> value is written.  The entry point is parse_options(), which scans through
>> the given argv, and matches each option there against the list of valid
>> options.  During the scan, argv is rewritten to only contain the
>> non-option command line arguments and the number of these is returned.
>> 
>> Aggregation of single switches is allowed:
>>   -rC0 is the same as -r -C 0 (supposing that -C wants an arg).
>
> I like options aggregation, but I'm not sure aggregating option arguments
> is a good idea... I can't even think of an application that does it.

I think most allow this for the last option in a row. Tar is somewhat more perverse with its non-option command string:

tar xfzbv filename.tgz 40

uses filename.tgz as the option argument for "f" and 40 for "b".

Note that while tar accepts options instead of the initial command string,

tar -xfzbv filename.tgz 40

will _not_ work, while

tar -xffilename.tgz -z -b40 -v

presumably would (have no time to test this right now).

-- 
David Kastrup