@Override
      public void run() {
        History h = reader.getHistory();
        if (h instanceof FileHistory) {
          try {
            ((FileHistory) h).flush();
          } catch (IOException e) {
            System.err.println("WARNING: Failed to write command history file: " + e.getMessage());
          }
        }
      }
Execute the cli work
@param ss CliSessionState of the CLI driver
@param conf HiveConf for the driver session
@param oproc Operation processor of the CLI invocation
@return status of the CLI command execution
@throws Exception
cli/src/java/org/apache/hadoop/hive/cli/CliDriver.java