private static void printUsage() {
    System.err.println("ExecDriver -plan <plan-file> [-jobconffile <job conf file>]"
        + "[-files <file1>[,<file2>] ...]");
    System.exit(1);
  }
Set hive input format, and input format file if necessary.
ql/src/java/org/apache/hadoop/hive/ql/exec/mr/ExecDriver.java