This example will print out the real group id, even once the effective
group id has been changed.
<?php echo 'My real group id is '.posix_getgid(); //20 posix_setegid(40); echo 'My real group id is '.posix_getgid(); //20 echo 'My effective group id is '.posix_getegid(); //40 ?>
See Also
posix_getgrgid() for information on how
to convert this into a useable group name