2.11BSD#431 - /usr/man/cat2/setgid.0

SETUID(2)	    UNIX Programmer's Manual		SETUID(2)


NAME
     setuid, seteuid,setgid,setegid - set user and group ID

SYNOPSIS
     #include <sys/types.h>
     #include <unistd.h>

     int
     setuid(uid)
	 uid_t uid

     int
     seteuid(euid)
	 uid_t euid

     int
     setgid(gid)
	 gid_t gid

     int
     setegid(egid)
	 gid_t egid

DESCRIPTION
     The setuid function sets the real and effective user IDs and
     the saved set-user-ID of the current process to the speci-
     fied value.  The setuid function is permitted if the speci-
     fied ID is equal to the real user ID of the process, or if
     the effective user ID is that of the super user.

     The 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.

     The seteuid function (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 intro(2) and 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 revert-
     ing 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-user-ID.

RETURN VALUES
     Upon success, these functions return 0; otherwise -1 is
     returned.

     If the user is not the super user, or the uid specified is
     not the real, effective ID, or saved ID, these functions


Printed 11/26/99	December 3, 1997			1


SETUID(2)	    UNIX Programmer's Manual		SETUID(2)


     return -1.

SEE ALSO
     getuid(2), getgid(2)

STANDARDS
     The setuid and setgid functions are compliant with the IEEE
     Std 1003.1-1988 (``POSIX'') specification with
     _POSIX_SAVED_IDS not defined.  The seteuid and setegid func-
     tions are extensions based on the POSIX concept of
     _POSIX_SAVED_IDS , and have been proposed for a future revi-
     sion of the standard.


Printed 11/26/99	December 3, 1997			2