setuid, setgid - set user and group ID
The user ID (group ID) of the current process is set to the argument.
Both the effective and the real ID are set. These calls are only per-
mitted to the super-user or if the argument is the real ID.
Zero is returned if the user (group) ID is set; -1 is returned other-
(setuid = 23.)
(user ID in r0)
(setgid = 46.)
(group ID in r0)