posix_setegid
    (PHP 4 >= 4.0.2, PHP 5)
posix_setegid -- 
     Set the effective GID of the current process
    
Description
bool 
posix_setegid ( int gid)
     Set the effective group ID of the current process. This is a
     privileged function and you need appropriate privileges (usually
     root) on your system to be able to perform this function.
    
     Returns TRUE on success or FALSE on failure.