/**
   * scans a Grib file to gather information that could be used to create an index or dump the
   * metadata contents.
   *
   * @param parm
   * @throws NotSupportedException
   * @throws IOException if raf does not contain a valid GRIB record
   */
  public final boolean scan(int[] parm) throws NotSupportedException, IOException {
    long start = System.currentTimeMillis();
    // stores the number of times a particular GDS is used
    HashMap gdsCounter = new HashMap();
    Grib1ProductDefinitionSection pds = null;
    Grib1GridDefinitionSection gds = null;
    long gdsOffset = 0;
    DataOutputStream dos = new DataOutputStream(System.out);

    // System.out.println("file position =" + raf.getFilePointer());
    long SOR = raf.getFilePointer();
    while (raf.getFilePointer() < raf.length()) {
      SOR = raf.getFilePointer();
      if (seekHeader(raf, raf.length())) {
        // Read Section 0 Indicator Section
        Grib1IndicatorSection is = new Grib1IndicatorSection(raf);
        // System.out.println( "Grib record length=" + is.getGribLength());
        // EOR (EndOfRecord) calculated so skipping data sections is faster
        long EOR = raf.getFilePointer() + is.getGribLength() - is.getLength();
        // long SOR = raf.getFilePointer() - is.getLength();

        // skip Grib 2 records in a Grib 1 file
        if (is.getGribEdition() == 2) {
          // System.out.println( "Error Grib 2 record in Grib1 file" ) ;
          raf.seek(EOR);
          continue;
        }

        if (parm[0] == -1) { // extract only 1st record
          raf.seek(SOR);
          byte[] oneRecord = new byte[(int) is.getGribLength()];
          raf.read(oneRecord);
          dos.write(oneRecord, 0, oneRecord.length);
          dos.flush();
          break;
        }
        long dataOffset = 0;
        try { // catch all exceptions and seek to EOR

          // Read Section 1 Product Definition Section PDS
          pds = new Grib1ProductDefinitionSection(raf);
          if (pds.getLengthErr()) {
            raf.seek(EOR);
            continue;
          }
          Grib1PDSVariables pdsv = pds.getPdsVars();
          if (getParameter && parm[0] == pdsv.getParameterNumber()) {
            raf.seek(SOR);
            byte[] oneRecord = new byte[(int) is.getGribLength()];
            raf.read(oneRecord);
            dos.write(oneRecord, 0, oneRecord.length);
            dos.flush();
          } else if (parm[0] <= pdsv.getForecastTime() && parm[1] >= pdsv.getForecastTime()) {
            raf.seek(SOR);
            byte[] oneRecord = new byte[(int) is.getGribLength()];
            raf.read(oneRecord);
            dos.write(oneRecord, 0, oneRecord.length);
            dos.flush();
          }

          raf.seek(EOR);
          continue;

        } catch (Exception e) {
          // .println( "Caught Exception scannning record" );
          e.printStackTrace();
          raf.seek(EOR);
          continue;
        }
      } // end if seekHeader
      // System.out.println( "raf.getFilePointer()=" + raf.getFilePointer());
      // System.out.println( "raf.length()=" + raf.length() );
    } // end while raf.getFilePointer() < raf.length()
    // System.out.println("GribInput: processed in " +
    //   (System.currentTimeMillis()- start) + " milliseconds");
    dos.close();
    return true;
  } // end scan