#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>
/* check for whether caller is a specific uid (numeric) */
int
main(int argc, char *argv[])
{
int uid = 0;
if (argc > 1)
uid = atoi(argv[1]);
exit(getuid() == uid ? 0 : 1);
}