Re: [help-gengetopt] how to deal with shared parameters for multiple programs?

[Lorenzo Bettini]

On 01/02/2011 04:12 PM, Erik Sjölund wrote:
> Hi,
> Suppose you have two different programs that share a subset of the
> command line parameters. For instance
>
> option "num1" f "some info" float
> option "num2" f "some info" float
>
> The shared command line parameters are used by a function that both
> programs use.
> One (somewhat sketchy) solution could be:
>
> struct CommonFlags {
>    float my_num1;
>    float my_num2;
> };
>
> void myFunction(struct commonFlags *common_flags) {
> }
>
> struct gengetopt_args_info args_info;
>    if(cmdline_parser(argc2, argv2,&args_info) != 0) {
>      exit(1);
> }
>
> CommonFlags common_flags;
> common_flags.my_num1 = args_info.num1;
> common_flags.my_num2 = args_info.num2;
> myFunction(&common_flags);
>
>
> But it would be nicer if I would not have to define my own struct CommonFlags.
>
> I could avoid that if the two different
> struct gengetopt_args_info
> that are generated for the two different programs could have some
> common struct as a member.
> (That common struct would contain the common flags).
>
> I guess this is not possible with the current version of gengetopt.
> cheers,
> Erik

Hi Erik

I think a possible solution is to allow a .ggo file to include another 
one, which is something is still to be implemented in gengetopt...

however, this would have the same semantics of C include, and would only 
copy the contents of the included .ggo file.

implementation of such include feature would be quite easy...

otherwise, that include, in order to have what you need, should have a 
semantics similar to C++ inheritance which is not possible in C...

or, as you suggest, to have pointer to the common struct... that 
semantics of include would require a more involved implementation 
though...  I guess at least...

do you have other ideas?

Note, however, that the generated struct passed to the generated parser 
is not thought to be used by other functions...  but only to collect 
command line arguments and values...  those values are better to be 
copied into your own variables

hope to hear from you soon
        Lorenzo

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Lorenzo Bettini, PhD in Computer Science, DI, Univ. Torino
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