CALL SEQUENCE...
       xfind  XFILE XOUT INPUT OUTPUT [-label "VAL" -def]
 
 
      AUTHOR  - J.D.Henderson, APR 08/81.
      LAST REVISION: $Header: /home/cvs/RMNLIB/utils/rdiag/lspgm/xfind.ptn,v 4.16 2014/09/25 20:20:56 dugas Exp $
 
 
      PURPOSE - FINDS SUPERLABELLED SETS ON FILE XFILE AND COPIES THEM TO 
                FILE XOUT IN THE ORDER REQUESTED ON CARDS. 
 
 
      INPUT FILE... 
 
       XFILE = CONTAINS MULTI-LEVEL SETS OF GRIDS, CROSS-SECTIONS ,ETC. 
               EACH SET IS PRECEDED BY A CHARACTER SUPERLABEL OR 
               ASSOCIATED TO A PARTICULAR ETIKET.
 
      OUTPUT FILE... 
       XOUT  = ONE SET COPIED FROM FILE XFILE 
 
 
      INPUT PARAMETERS... 
 
       ** ANYONE WHO MAKES USE OF THE FIRST FOUR CHARACTERS IN THE LABEL **
       **      (i.e. ISWTCH AND DUMMY) HAS TO DO SO VERY CAREFULLY       **
 
       ISWTCH = EXIT CONTROL SWITCH WHICH MUST BE '0', ' ' OR '1'. 
                0 OR BLANK - NORMAL ABORT IF REQUESTED FIELD IS NOT FOUND. 
                1          - WARNING EXIT IF REQUESTED FIELD IS NOT FOUND.
                OTHERWISE  - IMMEDIATE START OF LABEL.
       DUMMY  = IF ISWTCH IS 0,1 OR BLANK, MUST CONSIST OF 3 BLANK CHARACTERS
 
       SPRLBL = CHARACTER SUPERLABEL OF SET TO BE FOUND ON XFILE. 
       ====> IF ISWTCH IS 0,1 OR BLANK, SUPERLABELS START IN COLUMN 15 <====
 
       NOTES: 1) ANY FOUR CONSECUTIVE STARS DENOTE DON'T CARE CONDITIONS.
                 THE SAME IS ALSO TRUE FOR BLANK CONTINUATION WHEN THE
                 "def" PARAMETER IS SPECIFIED ON THE COMMAND LINE.
              2) IF "label" IS SPECIFIED AT CALL TIME, IT'S VALUE 
                 IS PASSED TO ISTCH,DUMMY AND SPRLBL, AS IS.
              3) THE ISWTCH/DUMMY ARRANGEMENT IS NOT AVAILABLE FOR
                 STANDARD SEQUENTIAL FILES.
              4) LEADING BLANKS ARE IGNORED IN SPRLBL WHEN XFIND IS USED
                 WITH STANDARD SEQUENTIAL FILES.
 
 
       READ( 5,5010 ) SWTCH,DUMMY,SPRLBL
 5010  FORMAT(10X,A1,A3,A252) 
 
 
      EXAMPLE OF INPUT CARD... 
 
  XFIND.  1   OBSERVED TEMPERATURE CROSS-SECTION (JAN) 
 
         0123456789012345678901234567890123456789012345678901234567890
         1         2         3         4         5         6         7
 
 
      EXIT CONDITIONS...
        0 NO PROBLEMS
        1 DUMMY NOT BLANK AND ISWTCH=0 OR 1
        2 EMPTY SUPERLABEL REQUESTED
        3 ABORT ERROR READIND XFILE (AND ISWTCH =0 )
        4 ABORT ERROR READIND REQUESTED SET ON XFILE (AND ISWTCH =0 )
        5 PREMATURE EOF ON XFILE
        6 CANNOT CHANGE PACKING TYPE