Re: Arrays of array references in inline C and perl

[Nitin Madnani]

Thanks to Sisyphus & Eric Wilhelp for excellent answers to my question !!
I have another (I think the answer is no, but I just wanted to be sure 
since I could not find anything in the mailing list) :

Is it possible to access global variables declared in perl space from an 
Inlined C function ?

Thanks !
Nitin
Sisyphus wrote:
Nitin Madnani wrote:
An interesting question - and one I was unable to answer off the top of 
my head. Here's something that works. I've used a different script 
layout ... but that's not part of the solution .... it's just that I 
always arrange things like this :-)

use warnings;
use Inline C => Config =>
    BUILD_NOISY => 1; # to make sure we get to
                      # see compiler warnings
use Inline C => <<'END_OF_C_CODE';
void add_one(AV * arri) {
int leni, lenj, i, j, t;
AV * arrj;
SV ** elemi, **elemj;
leni = av_len(arri) + 1;
for(i = 0; i < leni; ++i) {
   elemi = av_fetch(arri, i, 0);
   if(elemi == NULL) croak("Got a NULL in arri");
   arrj = (AV*)SvRV(*elemi);
   lenj = av_len(arrj) + 1;
   for(j = 0; j < lenj; ++j) {
      elemj = av_fetch(arrj, j, 0);
      if(elemj != NULL) {
        t = (int)SvIV(*elemj);
    t++;
    sv_setiv(*elemj, t);
        }
      else croak("Got a NULL in arrj");
      }
   }
}
void get_arr(SV* arr) {
int i, leni;
AV * arref;
SV ** elem;
arref = (AV *)SvRV(arr);
leni = av_len(arref) + 1;
for(i = 0; i < leni; ++i) {
   elem = av_fetch(arref, i, 0);
   if(elem != NULL) printf("%d ", (int)SvIV(*elem));
   else croak("Got a NULL in get_arr()");
   }
printf("\n");
}
END_OF_C_CODE
my @one = (1,2,3,4);
my @two = (10,20,30,40,50);
my @three = (19,29,39,49,59,69);
my @numarr = ([EMAIL PROTECTED], [EMAIL PROTECTED], [EMAIL PROTECTED]);
get_arr([EMAIL PROTECTED]);
get_arr([EMAIL PROTECTED]);
get_arr([EMAIL PROTECTED]);
add_one([EMAIL PROTECTED]);
print "@[EMAIL PROTECTED]@three\n";
__END__
Note that 'add_one()' takes an AV* as its argument. I've done 
'get_arr()' just as a simple example of how to get at the values when 
the array reference is passed as an SV* (instead of an AV*).

There are no doubt inefficiencies in both subs (eg unnecessary copying) 
- but it's a start. Hope it helps.

Cheers,
Rob