FUNCTION IREADMG(LUNIT,SUBSET,IDATE)

C$$$  SUBPROGRAM DOCUMENTATION BLOCK
C
C SUBPROGRAM:    IREADMG
C   PRGMMR: WOOLLEN          ORG: NP20       DATE: 1994-01-06
C

C ABSTRACT: THIS FUNCTION CALLS BUFR ARCHIVE LIBRARY SUBROUTINE READMG
C   AND PASSES BACK ITS RETURN CODE.  SEE READMG FOR MORE DETAILS.
C
C PROGRAM HISTORY LOG:
C 1994-01-06  J. WOOLLEN -- ORIGINAL AUTHOR
C 1999-11-18  J. WOOLLEN -- ADDED NEW FUNCTION ENTRY POINTS IREADMM AND
C                           IREADIBM
C 2002-05-14  J. WOOLLEN -- REMOVED ENTRY POINTS ICOPYSB, IREADFT,
C                           IREADIBM, IREADMM, IREADNS AND IREADSB
C                           (THEY BECAME SEPARATE ROUTINES IN THE
C                           BUFRLIB TO INCREASE PORTABILITY TO OTHER
C                           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:    IREADMG (LUNIT, SUBSET, IDATE)
C   INPUT ARGUMENT LIST:
C     LUNIT    - INTEGER: FORTRAN LOGICAL UNIT NUMBER FOR BUFR FILE
C
C   OUTPUT ARGUMENT LIST:
C     SUBSET   - CHARACTER*8: TABLE A MNEMONIC FOR TYPE OF BUFR MESSAGE
C                BEING READ
C     IDATE    - INTEGER: DATE-TIME STORED WITHIN SECTION 1 OF BUFR
C                MESSAGE BEING READ, IN FORMAT OF EITHER YYMMDDHH OR
C                YYYYMMDDHH, DEPENDING ON DATELEN() VALUE
C     IREADMG  - INTEGER: RETURN CODE:
C                       0 = normal return
C                      -1 = there are no more BUFR messages in LUNIT
C
C REMARKS:
C    THIS ROUTINE CALLS:        READMG
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$$$

      CHARACTER*8 SUBSET
      CALL READMG(LUNIT,SUBSET,IDATE,IRET)
      IREADMG = IRET
      RETURN
      END