/**
   * Main method for the program. Checks that input file is present and readable, then iterates
   * through the index printing meta data to stdout.
   */
  protected int doWork() {

    if (INPUT.getName().endsWith(BAMIndex.BAMIndexSuffix))
      log.warn("INPUT should be the BAM file name, not its index file");
    IOUtil.assertFileIsReadable(INPUT);
    BAMIndexMetaData.printIndexStats(INPUT);

    return 0;
  }