Entry point

def main():
    '''Entry point'''
    if len(sys.argv) == 1:
        print("Usage: tyler [filename]")
        sys.exit(0)
    filename = sys.argv[1]

    if not os.path.isfile(filename):
        print("Specified file does not exists")
        sys.exit(8)

    my_tyler = Tyler(filename=filename)
    while True:
        try:
            for line in my_tyler:
                print(line)
            time.sleep(1)
        except KeyboardInterrupt:
            print("Quit signal received")
            sys.exit(0)