PTY_handler.py 文件源码

def __init__(self, slave=0, pid=os.getpid()):
        # apparently python GC's modules before class instances so, here
        # we have some hax to ensure we can restore the terminal state.
        self.termios, self.fcntl = termios, fcntl

        # open our controlling PTY
        self.pty  = open(os.readlink("/proc/%d/fd/%d" % (pid, slave)), "rb+")

        # store our old termios settings so we can restore after
        # we are finished 
        self.oldtermios = termios.tcgetattr(self.pty)

        # get the current settings se we can modify them
        newattr = termios.tcgetattr(self.pty)

        # set the terminal to uncanonical mode and turn off
        # input echo.
        newattr[3] &= ~termios.ICANON & ~termios.ECHO

        # don't handle ^C / ^Z / ^\
        newattr[6][termios.VINTR] = '\x00'
        newattr[6][termios.VQUIT] = '\x00'
        newattr[6][termios.VSUSP] = '\x00'

        # set our new attributes
        termios.tcsetattr(self.pty, termios.TCSADRAIN, newattr)

        # store the old fcntl flags
        self.oldflags = fcntl.fcntl(self.pty, fcntl.F_GETFL)
        # fcntl.fcntl(self.pty, fcntl.F_SETFD, fcntl.FD_CLOEXEC)
        # make the PTY non-blocking
        fcntl.fcntl(self.pty, fcntl.F_SETFL, self.oldflags | os.O_NONBLOCK)