Example of Core Merging Routine

  program MERGEFILE (input,output);

  {This program reads the files, TEMPEMP and PERMEMP, merges}
  {them by employee number, and outputs to the file, ALLEMP }

  var
     tempFileNum: INTEGER;
     permFileNum: INTEGER;
     outFileNum : INTEGER;
     status     : INTEGER;

  procedure HPFOPEN  ; intrinsic;
  procedure HPMERGEINIT; intrinsic;
  procedure HPMERGEERRORMESS; intrinsic;
  procedure HPMERGEEND; intrinsic;
  procedure FCLOSE; intrinsic;


  procedure OPEN_FILES;

  const
     designator  = 2;
     domain      = 3;
     access      = 11;
     record_size = 19;

  var
     tempFile  : packed array [1..10] of CHAR;
     permFile  : packed array [1..10] of CHAR;
     outFile   : packed array [1..10] of CHAR;
     permanent : INTEGER;
     new       : INTEGER;
     write     : INTEGER;
     size      : INTEGER;
     tempFile := '%TEMPEMP%';
     permanent := 1;
     HPFOPEN (tempFileNum, status, designator, tempFile, domain,
              permanent);

     permFile := '%PERMEMP%';
     HPFOPEN (permFileNum, status, designator, permFile, domain,
              permanent);
     new := 4;
     write := 1;
     size := 80;
     outFile := '%ALLEMP%';
     HPFOPEN (oOutFileNum, status, designator, outFile, domain, new,
              access, write, record_size, size);
  end;


  procedure DO_MERGE;

  var
     inputfiles   : array [1..3] of INTEGER;
     outputfile   : array [1..2] of INTEGER;
     keysonly     : INTEGER;
     numKeys      : INTEGER;
     keys         : array [1..4] of INTEGER;
     altseq       : packed array [1..2] of CHAR;
     message      : packed array [1..80] of CHAR;
     length       : INTEGER;

  begin
     inputfiles [1] := tempFileNum;
     inputfiles [2] := permFileNum;
     inputfiles [3] := 0;

     outputfile [1] := outFileNum;                    {from HPFOPEN}
     outputfile [2] := 0;

     keysonly := 0;      {output record format same as input record}
     numKeys := 1;                                         {one key}
     keys[1] := 41;                                     {key begins}
     keys[2] := 20;                                     {key length}
     keys[3] := 0;                                       {byte data}
     keys[4] := 0;                                 {ascending order}

     altseq[1] := CHR(255);         {data = ASCII; sequence = ASCII}
     altseq[2] := CHR(255);                {256 characters in ASCII}
     HPMERGEINIT (status, inputfiles,, outputfile,, keysonly,
                  numKeys, keys, altseq,,,,,);
     if status <> 0 then             {if error in HPMERGEINIT}
     begin                      {get message and print it to screen}
        message := ' ';
        HPMERGEERRORMESS (status, message, length);
        writeln (Message);
     end;

     HPMERGEEND (status, statistics);
     if status <> 0 then              {if error in HPMERGEEND}
     begin                      {get message and print it to screen}
        message := ' ';
        HPMERGEERRORMESS (status, message, length);
        writeln (message);
     end;
  end;


  procedure CLOSE_FILES;

  var
     disposition : SHORTINT;
     securityCode : SHORTINT;

  begin
     disposition := 0;
     securityCode := 0;
     FCLOSE (tempFileNum, disposition, securityCode);
     FCLOSE (permFileNum, disposition, securityCode);
     disposition := 1;
     FCLOSE (outFileNum, disposition, securityCode);

  end;


  begin {main}
     OPEN_FILES;
     DO_MERGE;
     CLOSE_FILES;
  end.