Python termios.TIOCSCTTY Examples

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):
        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()
    # pylint: disable=not-an-iterable
    p = yield from asyncio.create_subprocess_exec(*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 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()
    # pylint: disable=subprocess-popen-preexec-fn
    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 _acquire_controlling_tty():
    os.setsid()
    if sys.platform in ('linux', 'linux2'):
        # On Linux, the controlling tty becomes the first tty opened by a
        # process lacking any prior tty.
        os.close(os.open(os.ttyname(2), os.O_RDWR))
    if hasattr(termios, 'TIOCSCTTY') and not mitogen.core.IS_WSL:
        # #550: prehistoric WSL does not like TIOCSCTTY.
        # On BSD an explicit ioctl is required. For some inexplicable reason,
        # Python 2.6 on Travis also requires it.
        fcntl.ioctl(2, termios.TIOCSCTTY) 

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() 

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() 

def _setupChild(self, masterfd, slavefd):
        """
        Setup child process after fork() but before exec().
        """
        os.close(masterfd)
        if hasattr(termios, 'TIOCNOTTY'):
            try:
                fd = os.open("/dev/tty", os.O_RDWR | os.O_NOCTTY)
            except OSError:
                pass
            else:
                try:
                    fcntl.ioctl(fd, termios.TIOCNOTTY, '')
                except:
                    pass
                os.close(fd)

        os.setsid()

        if hasattr(termios, 'TIOCSCTTY'):
            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()


    # PTYs do not have stdin/stdout/stderr. They only have in and out, just
    # like sockets. You cannot close one without closing off the entire PTY.