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 su-
          peruser, 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 su-
          peruser, 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 effec-
          tive 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.

     RETURN VALUE
          On successful completion, a value of 0 is returned.  Other-
          wise, a value of -1 is returned and errno is set to indicate
          the error.

     ERRORS
          setuid or setgid will fail if one or more of the following
          are 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.



     April, 1990                                                     1

     setuid(2)                                               setuid(2)



          [EINVAL]  uid is out of range.

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



















































     2                                                     April, 1990