> If no commands are entered, you will be prompted for a file name.
'''
arg_parser = argparse.ArgumentParser(
description="Extract filename if present")
arg_parser.add_argument("-f",
"--file",
help="Name of the file",
default=None)
args = arg_parser.parse_args()
the_exception_handler = TigrExceptionHandler(
"TIGr encountered an error and had to exit")
if args.file:
# file name provided - read input from file
TigrReader(RegexParser(CommandFactory(TurtleDrawer()),
the_exception_handler),
the_exception_handler,
optional_file_name=args.file).go()
else:
# read from stdin
# TODO examine if this section of the code can be incorporated within the class structure
source = None
if sys.stdin.isatty():
# read from input at prompt
print("Enter your commands. Ctrl + Z to exit or finish.")
# only on windows, if this was portable we should add the linux interrupt command x3
print(
"If no commands are entered, you will be prompted for a file name."
)
source = sys.stdin.readlines()
