parameters: (filename)
return_statement: return ftype
docstring: Classify the file named by 'filename' and return the classification.
      If the file is classified as 'IT_Invalid' print an error message and exit
      the program.
docstring_summary: Classify the file named by 'filename' and return the classification.
      If the file is classified as 'IT_Invalid' print an error message and exit
      the program.
docstring_tokens: Classify the file named by filename and return the classification . If the file is classified as IT_Invalid print an error message and exit the program .
function: def check_input_file(filename):
      """
      Classify the file named by 'filename' and return the classification.
      If the file is classified as 'IT_Invalid' print an error message and exit
      the program.
      """
      ftype, msg = classify_input_file(filename)
      if ftype == IT_Invalid:
          print("Invalid input file: %s" % msg)
          sys.exit(1)
      return ftype
function_tokens: def check_input_file ( filename ) : ftype , msg = classify_input_file ( filename ) if ftype == IT_Invalid : print ( "Invalid input file: %s" % msg ) sys . exit ( 1 ) return ftype