docs: private static void trueMain(String[] argv) throws Exception {
      if (argv.length != 1) {
        System.err.println("Please provide a params file as the sole command line argument");
        System.exit(-1);
      }
      final Parameters params = Parameters.loadSerifStyle(new File(argv[0]));
  
      final File outputDirectory = params.getCreatableDirectory("outputDirectory");
      final File corpusRoot = params.getExistingDirectory("corpusRoot");
      final int memory = params.getPositiveInteger("memoryInMB");
      final boolean storeDocs = params.getBoolean("storeDocs");
      final Predicate<File> fileFilter = getFileFilter(params);
      final IndriFileProcessor indriFileProcessor = params.getParameterInitializedObject(
          "indriFileProcessorClass", IndriFileProcessor.class);
  
      log.info("Building index for corpus {} format to {} using processor {}",
          corpusRoot, outputDirectory, indriFileProcessor.getClass().getName());
  
      final IndexEnvironment env = setupIndexer(outputDirectory, memory, storeDocs);
  
      recursiveIndex(corpusRoot, env, indriFileProcessor,
          fileFilter);
      log.info("Indexed {} documents", env.documentsIndexed());
      env.close();
      log.info("Index complete");
    }