View file File name : _fork_pty.py Content :"""Substitute for the forkpty system call, to support Solaris. """ import os import errno from pty import (STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO, CHILD) def fork_pty(): '''This implements a substitute for the forkpty system call. This should be more portable than the pty.fork() function. Specifically, this should work on Solaris. Modified 10.06.05 by Geoff Marshall: Implemented __fork_pty() method to resolve the issue with Python's pty.fork() not supporting Solaris, particularly ssh. Based on patch to posixmodule.c authored by Noah Spurrier:: http://mail.python.org/pipermail/python-dev/2003-May/035281.html ''' parent_fd, child_fd = os.openpty() if parent_fd < 0 or child_fd < 0: raise OSError("os.openpty() failed") pid = os.fork() if pid == CHILD: # Child. os.close(parent_fd) pty_make_controlling_tty(child_fd) os.dup2(child_fd, STDIN_FILENO) os.dup2(child_fd, STDOUT_FILENO) os.dup2(child_fd, STDERR_FILENO) else: # Parent. os.close(child_fd) return pid, parent_fd def pty_make_controlling_tty(tty_fd): '''This makes the pseudo-terminal the controlling tty. This should be more portable than the pty.fork() function. Specifically, this should work on Solaris. ''' child_name = os.ttyname(tty_fd) # Disconnect from controlling tty, if any. Raises OSError of ENXIO # if there was no controlling tty to begin with, such as when # executed by a cron(1) job. try: fd = os.open("/dev/tty", os.O_RDWR | os.O_NOCTTY) os.close(fd) except OSError as err: if err.errno != errno.ENXIO: raise os.setsid() # Verify we are disconnected from controlling tty by attempting to open # it again. We expect that OSError of ENXIO should always be raised. try: fd = os.open("/dev/tty", os.O_RDWR | os.O_NOCTTY) os.close(fd) raise ExceptionPexpect("OSError of errno.ENXIO should be raised.") except OSError as err: if err.errno != errno.ENXIO: raise # Verify we can open child pty. fd = os.open(child_name, os.O_RDWR) os.close(fd) # Verify we now have a controlling tty. fd = os.open("/dev/tty", os.O_WRONLY) os.close(fd)