Python termios 模块，TIOCSCTTY 实例源码

def launch_proc_with_pty(args, stdin=None, stdout=None, stderr=None, echo=True):
    """Similar to pty.fork, but handle stdin/stdout according to parameters
    instead of connecting to the pty

    :return tuple (subprocess.Popen, pty_master)
    """

    def set_ctty(ctty_fd, master_fd):
        '''Set controlling terminal'''
        os.setsid()
        os.close(master_fd)
        fcntl.ioctl(ctty_fd, termios.TIOCSCTTY, 0)
        if not echo:
            termios_p = termios.tcgetattr(ctty_fd)
            # termios_p.c_lflags
            termios_p[3] &= ~termios.ECHO
            termios.tcsetattr(ctty_fd, termios.TCSANOW, termios_p)
    (pty_master, pty_slave) = os.openpty()
    p = subprocess.Popen(args, stdin=stdin, stdout=stdout,
        stderr=stderr,
        preexec_fn=lambda: set_ctty(pty_slave, pty_master))
    os.close(pty_slave)
    return p, open(pty_master, 'wb+', buffering=0)

def prepare():
    os.setsid()
    fcntl.ioctl(sys.stdin, termios.TIOCSCTTY, 0)

def prepare():
    os.setsid()
    fcntl.ioctl(sys.stdin, termios.TIOCSCTTY, 0)

def _setup_slave_pty(self):
        """Set suitable tty options for our pty slave
        """
        os.setsid()
        fcntl.ioctl(self.slave, termios.TIOCSCTTY, 0)
        os.close(self.master)
        os.dup2(self.slave, STDIN)
        os.dup2(self.slave, STDOUT)
        os.dup2(self.slave, STDERR)  # FIXME can we handle stderr better?
        os.close(self.slave)

def _setupChild(self, masterfd, slavefd):
        """
        Set up child process after C{fork()} but before C{exec()}.

        This involves:

            - closing C{masterfd}, since it is not used in the subprocess

            - creating a new session with C{os.setsid}

            - changing the controlling terminal of the process (and the new
              session) to point at C{slavefd}

            - duplicating C{slavefd} to standard input, output, and error

            - closing all other open file descriptors (according to
              L{_listOpenFDs})

            - re-setting all signal handlers to C{SIG_DFL}

        @param masterfd: The master end of a PTY file descriptors opened with
            C{openpty}.
        @type masterfd: L{int}

        @param slavefd: The slave end of a PTY opened with C{openpty}.
        @type slavefd: L{int}
        """
        os.close(masterfd)
        os.setsid()
        fcntl.ioctl(slavefd, termios.TIOCSCTTY, '')

        for fd in range(3):
            if fd != slavefd:
                os.close(fd)

        os.dup2(slavefd, 0) # stdin
        os.dup2(slavefd, 1) # stdout
        os.dup2(slavefd, 2) # stderr

        for fd in _listOpenFDs():
            if fd > 2:
                try:
                    os.close(fd)
                except:
                    pass

        self._resetSignalDisposition()