      FUNCTION IREADSB(LUNIT)

C$$$  SUBPROGRAM DOCUMENTATION BLOCK
C
C SUBPROGRAM:    IREADSB
C   PRGMMR: WOOLLEN          ORG: NP20       DATE: 1994-01-06
C
C ABSTRACT: THIS FUNCTION CALLS BUFR ARCHIVE LIBRARY SUBROUTINE READSB
C   AND PASSES BACK ITS RETURN CODE.  SEE READSB FOR MORE DETAILS.
C
C PROGRAM HISTORY LOG:
C 1994-01-06  J. WOOLLEN -- ORIGINAL AUTHOR (ENTRY POINT IN IREADMG)
C 2002-05-14  J. WOOLLEN -- CHANGED FROM AN ENTRY POINT TO INCREASE
C                           PORTABILITY TO OTHER PLATFORMS
C 2003-11-04  S. BENDER  -- ADDED REMARKS/BUFRLIB ROUTINE
C                           INTERDEPENDENCIES
C 2003-11-04  D. KEYSER  -- UNIFIED/PORTABLE FOR WRF; ADDED
C                           DOCUMENTATION (INCLUDING HISTORY)
C
C USAGE:    IREADSB (LUNIT)
C   INPUT ARGUMENT LIST:
C     LUNIT    - INTEGER: FORTRAN LOGICAL UNIT NUMBER FOR BUFR FILE
C
C   OUTPUT ARGUMENT LIST:
C     IREADSB  - INTEGER: RETURN CODE:
C                       0 = normal return
C                      -1 = there are no more subsets in the BUFR
C                           message
C
C REMARKS:
C    THIS ROUTINE CALLS:        READSB
C    THIS ROUTINE IS CALLED BY: UFBTAB
C                               Also called by application programs.
C
C ATTRIBUTES:
C   LANGUAGE: FORTRAN 77
C   MACHINE:  PORTABLE TO ALL PLATFORMS
C
C$$$

      CALL READSB(LUNIT,IRET)
      IREADSB = IRET
      RETURN
      END
