Add pexpect-2.3 to third_party

third_party/pexpect/fdpexpect.py

+"""This is like pexpect, but will work on any file descriptor that you pass it.
+So you are reponsible for opening and close the file descriptor.
+
+$Id: fdpexpect.py 505 2007-12-26 21:33:50Z noah $
+"""
+
+from pexpect import *
+import os
+
+__all__ = ['fdspawn']
+
+class fdspawn (spawn):
+
+    """This is like pexpect.spawn but allows you to supply your own open file
+    descriptor. For example, you could use it to read through a file looking
+    for patterns, or to control a modem or serial device. """
+
+    def __init__ (self, fd, args=[], timeout=30, maxread=2000, searchwindowsize=None, logfile=None):
+
+        """This takes a file descriptor (an int) or an object that support the
+        fileno() method (returning an int). All Python file-like objects
+        support fileno(). """
+
+        ### TODO: Add better handling of trying to use fdspawn in place of spawn
+        ### TODO: (overload to allow fdspawn to also handle commands as spawn does.
+
+        if type(fd) != type(0) and hasattr(fd, 'fileno'):
+            fd = fd.fileno()
+
+        if type(fd) != type(0):
+            raise ExceptionPexpect ('The fd argument is not an int. If this is a command string then maybe you want to use pexpect.spawn.')
+
+        try: # make sure fd is a valid file descriptor
+            os.fstat(fd)
+        except OSError:
+            raise ExceptionPexpect, 'The fd argument is not a valid file descriptor.'
+
+        self.args = None
+        self.command = None
+        spawn.__init__(self, None, args, timeout, maxread, searchwindowsize, logfile)
+        self.child_fd = fd
+        self.own_fd = False
+        self.closed = False
+        self.name = '<file descriptor %d>' % fd
+
+    def __del__ (self):
+
+        return
+
+    def close (self):
+
+        if self.child_fd == -1:
+            return
+        if self.own_fd:
+            self.close (self)
+        else:
+            self.flush()
+            os.close(self.child_fd)
+            self.child_fd = -1
+            self.closed = True
+
+    def isalive (self):
+
+        """This checks if the file descriptor is still valid. If os.fstat()
+        does not raise an exception then we assume it is alive. """
+
+        if self.child_fd == -1:
+            return False
+        try:
+            os.fstat(self.child_fd)
+            return True
+        except:
+            return False
+
+    def terminate (self, force=False):
+
+        raise ExceptionPexpect ('This method is not valid for file descriptors.')
+
+    def kill (self, sig):
+
+        return
+