patch to use net options

[Henrik Nordstrom]

On Tue, 24 May 2005, Rafal Szczesniak wrote:

>> It seems that there's no subcommand options support in popt. I can make 
>> a mistake but I didn't find any.
>
> OK, thanks. We'll probably need to do as I initially thought.

>From my understanding of the problem one is supposed to just grab the 
remaining arguments and send them as input to the sub-command which then 
does it's own popt processing. To support common options include the 
common options in the sub-commands popt table with the help of the 
POPT_ARG_INCLUDE_TABLE argInfo type.

General structure:

   main popt table called with initial argv in POPT_CONTEXT_POSIXMEHARDER 
mode. This has the global options which must/should go before the 
sub-command identifier.

   when a non-option argument is encountered then it's the sub-command. 
Grab the remaining arguments and send this as argv to the sub-command. 
Thanks to POPT_CONTEXT_POSIXMEHARDER any options after the sub-command is 
left intact.

   in the sub-command popt table (parsed with POPT_CONTEXT_KEEP_FIRST as 
there is no argv[0] here), include the common options as popt table(s) 
using POPT_ARG_INCLUDE_TABLE as appropriate for the sub-command in 
question. More than one such group may be supported, and includes may be 
nested to your liking.

   Included common option tables preferably uses the callback mechanism to 
process the options (POPT_ARG_CALLBACK) if special processing is required. 
This way no common options will be returned to the sub-command opion 
parser and the parsing of the common options is completely hidden to the 
sub-command.

This centralizes the common option groups quite nicely, only requiring 
each sub-command to indicate which group(s) of common options it supports 
in addition to it's own.

Problems arises if there us sub-command specific options which may go 
before the sub-command identifier. For sanity these should be handled as 
global options available to all sub-commands.

Only thing I see missing is a popt call to grab the remaining argc to send 
to the sub-command. Only argv is available. Trivial count up to NULL is 
sufficient but still oddly missing..

An example program showing this use of popt for sub-command option 
processing can be found here:
<url:http://www.henriknordstrom.net/examples/popt_subcommand.c>

Regards
Henrik