Providing C function With Argv

[jeff.huter@bigfoot.com (Jeff)]

I'm in the process of extending/porting a C program to Ada.  I have an
Ada main program that needs to call a C function with the parameters
int argc, char **argv.  With Ada.Command_Line, I've been able to pass
the C function with int argc.  Using Interfaces.C.Strings, I have even
been successful supplying a modified version of the C function with a
Interfaces.C.Strings.chars_ptr to provide the function with a single
string Argument.  However, I can't seem to figure out how to construct
and pass the equivalent of a C char ** in order to pass all the
arguments at once.  My guess is that I need to use
Interfaces.C.Pointers to construct a Pointer to chars_ptr.  But I've
had no luck with this approach.

How does one pass a C function the eqivalent of char **?  Is there any
easier way to accomplish this than to construct the char **argv from
Ada.Command_Line.Argument?  Working code would be much appreciated
since I'm rather new to Ada.