autoreload.py 文件源码

def ensure_echo_on():
    if termios:
        fd = sys.stdin
        if fd.isatty():
            attr_list = termios.tcgetattr(fd)
            if not attr_list[3] & termios.ECHO:
                attr_list[3] |= termios.ECHO
                if hasattr(signal, 'SIGTTOU'):
                    old_handler = signal.signal(signal.SIGTTOU, signal.SIG_IGN)
                else:
                    old_handler = None
                termios.tcsetattr(fd, termios.TCSANOW, attr_list)
                if old_handler is not None:
                    signal.signal(signal.SIGTTOU, old_handler)