Re: Allocating a char* and returning to Perl from a C function

[Steve Fink]

On Wed, Jul 30, 2008 at 12:16 PM, Sisyphus <[EMAIL PROTECTED]> wrote:
>
> Better to allocate/free memory using New/Safefree instead of malloc/free.

Why? That memory is never being seen by Perl. Why not leave it as-is,
if you're just going to free it anyway?

> use warnings;
> #use Devel::Peek;
>
> use Inline C => <<'EOC';
>
> SV * foo(char *x) {
>   SV * ret;
>   char * str2ret;
>   STRLEN len = strlen(x);
>
>   printf("%d\n", len);
>
>   New(0, str2ret, len * 2, char);
>   if(str2ret == NULL) croak("Failed to allocate memory for str2ret");
>
>   // Do stuff
>
>   ret = newSVpv(str2ret, len * 2);
>
>   Safefree(str2ret);
>   return ret;
> }
>
> EOC

This is untested, but wouldn't it be easier to just do:

SV* work(char* inString)
{
       SV* ret;
       char *stringToReturn = (char *)malloc(2*sizeof(inString)); // I
think you meant strlen? +1?

       while(*inString){
               // do some work on stringToReturn
               inString++;
       }
       ret = newSVpv(stringToReturn, 0); // or
newSVpvn(stringToReturn, 2 * strlen(inString)) or whatever
       free(stringToReturn);
       return ret;
}