#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <grp.h>
#include <errno.h>
#include <stdio.h>
#include <dirent.h>

int
main(int argc, char **argv)
{
  uid_t uid;
  gid_t gid;

  if (argc != 3)
    exit (1);

  if (setgroups (0, NULL) < 0)
    fprintf (stderr, "setgroups() failed: %s\n", strerror (errno));

  uid = atoi (argv[1]);
  gid = atoi (argv[2]);
  
  if (setgid (gid) < 0)
    fprintf (stderr, "setgid() failed: %s\n", strerror (errno));
    
  if (setuid (uid) < 0)
    fprintf (stderr, "setgroups() failed: %s\n", strerror (errno));

  execl ("/bin/sh", "/bin/sh", NULL);
  fprintf (stderr, "exec() failed: %s\n", strerror (errno));
  exit (1);
}