|SETUID(2)||System Calls Manual||SETUID(2)|
setuid() function sets the real and effective user IDs and the saved set-user-ID of the current process to the specified value. The
setuid() function is permitted if the specified ID is equal to the real user ID of the process, or if the effective user ID is that of the super user.
setgid() function sets the real and
effective group IDs and the saved set-group-ID of the current process to the
specified value. The
setgid() function is permitted
if the specified ID is equal to the real group ID of the process, or if the
effective user ID is that of the super user. Supplementary group IDs remain
setegid()) sets the effective user ID (group ID) of
the current process. The effective user ID may be set to the value of the
real user ID or the saved set-user-ID (see
execve(2)); in this way, the
effective user ID of a set-user-ID executable may be toggled by switching to
the real user ID, then re-enabled by reverting to the set-user-ID value.
Similarly, the effective group ID may be set to the value of the real group
ID or the saved set-group-ID.
If the user is not the super user, or the uid specified is not the real, effective ID, or saved ID, these functions return -1.
setgid() functions are compliant with the IEEE Std 1003.1-1990 (“POSIX.1”) specification with
_POSIX_SAVED_IDSnot defined. We do not implement the
_POSIX_SAVED_IDSoption as specified in the standard because this would make it impossible for a set-user-ID executable owned by a user other than the super-user to permanently revoke its privileges.
setegid() functions are compliant with
IEEE Std 1003.1-2001 (“POSIX.1”).
setgid() functions appeared in Version 2 AT&T UNIX and Version 4 AT&T UNIX, respectively.
|April 3, 2010||NetBSD-7.0.1|