Using a C function with command line parameters

[Steven Schveighoffer]

On Mon, 04 Jul 2011 10:31:58 -0400, Jonathan Sternberg  
<jonathansternberg at gmail.com> wrote:

> glut has the function:
>
>     void glutInit( int* pargc, char** argv );
>
> In order to use it. Since D has an ABI compatible with C, I should be  
> able to
> write a D file with extern (C) on the glut functions. How would I wrap  
> this
> function to be used with D arrays? Such as:
>
> int main(string[] args)
> {
>     glutInit( /* I don't know what to do here */ );
>     return 0;
> }
>
> Thanks.

Convert all the args to zero-terminated strings.  One thing to look at,  
does glutInit actually modify any of the strings or does it just remove  
them from the argv array?  Because I would expect the argv argument to be  
const(char)** if it doesn't modify.  That would allow you to pass in the  
strings without having to duplicate them.

Some untested code:

auto argarr = new immutable(char)*[args.length];
foreach(i, a; args)
    argarr[i] = (a.dup ~ '\0').ptr;

int argc = argarr.length;
glutInit(&argc, argarr.ptr);

// now, need to refix args to ignore arguments already consumed by glutInit
...

-Steve