execve

#include <stdio.h>
#include <unistd.h>

int main()
{
   int ret_val;
   char *newargv[] = {"ipfw", "add", "set", "21", "fwd", "127.0.0.1,59272", "tcp", "from", "any", "to", "any", "80", "in", "via", "en1", NULL };
   switch(fork()) {
      case 0:
         execvp(newargv[0], newargv);
         fprintf(stderr,"problem\n");
         _exit(0);
      case -1:
         fprintf(stderr,"fork failed!\n");
         break;
      default:
         fprintf(stderr,"waiting...\n");
         wait(&ret_val);
         fprintf(stderr,"exec returned!\n");
   }
   fprintf(stderr,"the return value has been %d",ret_val);
   return 0;
}