SETUID(2)                            SysV                            SETUID(2)



NAME
     setuid, setgid - set user and group IDs

SYNOPSIS
     int setuid (uid)
     int uid;

     int setgid (gid)
     int gid;

DESCRIPTION
     setuid (setgid) is used to set the real user (group) ID and effective
     user (group) ID of the calling process.

     If the effective user ID of the calling process is super-user, the real
     user (group) ID and effective user (group) ID are set to uid (gid).

     If the effective user ID of the calling process is not super-user, but
     its real user (group) ID is equal to uid (gid), the effective user
     (group) ID is set to uid (gid).

     If the effective user ID of the calling process is not super-user, but
     the saved set-user (group) ID from exec(2) is equal to uid (gid), the
     effective user (group) ID is set to uid (gid).

NOTES
     Under some implementations of the UNIX operating system, the setgid call
     will modify the supplementary group list.  This is not the case under
     Domain/OS.

     At login time, the user's native group is automatically added to the
     supplementary group list.  Therefore, a setgid call will leave the user
     in that original group (since the supplementary list is not changed).

ERRORS
     setuid (setgid) will fail if either of the following is true:

     [EPERM]    The real user (group) ID of the calling process is not equal
                to uid (gid) and its effective user ID is not super-user.

     [EINVAL]   The uid is out of range.

SEE ALSO
     intro(2), getoid(2), getuid(2), setoid(2).

DIAGNOSTICS
     Upon successful completion, a value of 0 is returned.  Otherwise, a value
     of -1 is returned and errno is set as indicated under "Errors."