setuid(2)                                               setuid(2)



NAME
     setuid, setgid - set user and group ID

SYNOPSIS
     #include <sys/types.h>

     uid_t setuid(uid)
     uid_t uid;

     int setgid(gid)
     gid_t gid;

DESCRIPTION
     setuid sets the real user ID, effective user ID, and saved
     set-user-ID of the calling process.  If the effective user
     ID of the calling process is superuser, the real user ID,
     effective user ID, and saved set-user-ID are set to uid.  If
     the effective user ID of the calling process is not the
     superuser, but its real user ID is equal to uid, the
     effective user ID is set to uid.

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

     setgid sets the real group ID, effective group ID, and saved
     set-group-ID of the calling process.

     If the effective user ID of the calling process is the
     superuser, the real group ID, effective group ID, and saved
     set-group-ID are set to gid.

     If the effective user ID of the calling process is not the
     superuser, but its real group ID is equal to gid, the
     effective group ID is set to gid.

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

STATUS MESSAGES AND VALUES
     On successful completion, a value of 0 is returned.
     Otherwise, a value of -1 is returned and errno is set to
     indicate the error.

     The setuid or setgid commands will fail if one or more of
     the following is true:

     EPERM
          The real user or group ID of the calling process is not
          equal to uid or gid and its effective user ID is not
          the superuser.



January 1992                                                    1

setuid(2)                                               setuid(2)



     EINVAL
          uid is out of range.

SEE ALSO
     getuid(2), intro(2), setregid(2), setreuid(2)


















































2                                                    January 1992