1 """This is like pexpect, but will work on any file descriptor that you pass it. 2 You are reponsible for opening and close the file descriptor. 3 4 PEXPECT LICENSE 5 6 This license is approved by the OSI and FSF as GPL-compatible. 7 http://opensource.org/licenses/isc-license.txt 8 9 Copyright (c) 2012, Noah Spurrier <noah (at] noah.org> 10 PERMISSION TO USE, COPY, MODIFY, AND/OR DISTRIBUTE THIS SOFTWARE FOR ANY 11 PURPOSE WITH OR WITHOUT FEE IS HEREBY GRANTED, PROVIDED THAT THE ABOVE 12 COPYRIGHT NOTICE AND THIS PERMISSION NOTICE APPEAR IN ALL COPIES. 13 THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 14 WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 15 MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 16 ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 17 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 18 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 19 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 20 21 """ 22 23 from pexpect import * 24 import os 25 26 __all__ = ['fdspawn'] 27 28 class fdspawn (spawn): 29 30 """This is like pexpect.spawn but allows you to supply your own open file 31 descriptor. For example, you could use it to read through a file looking 32 for patterns, or to control a modem or serial device. """ 33 34 def __init__ (self, fd, args=[], timeout=30, maxread=2000, searchwindowsize=None, logfile=None): 35 36 """This takes a file descriptor (an int) or an object that support the 37 fileno() method (returning an int). All Python file-like objects 38 support fileno(). """ 39 40 ### TODO: Add better handling of trying to use fdspawn in place of spawn 41 ### TODO: (overload to allow fdspawn to also handle commands as spawn does. 42 43 if type(fd) != type(0) and hasattr(fd, 'fileno'): 44 fd = fd.fileno() 45 46 if type(fd) != type(0): 47 raise ExceptionPexpect ('The fd argument is not an int. If this is a command string then maybe you want to use pexpect.spawn.') 48 49 try: # make sure fd is a valid file descriptor 50 os.fstat(fd) 51 except OSError: 52 raise ExceptionPexpect, 'The fd argument is not a valid file descriptor.' 53 54 self.args = None 55 self.command = None 56 spawn.__init__(self, None, args, timeout, maxread, searchwindowsize, logfile) 57 self.child_fd = fd 58 self.own_fd = False 59 self.closed = False 60 self.name = '<file descriptor %d>' % fd 61 62 def __del__ (self): 63 64 return 65 66 def close (self): 67 68 if self.child_fd == -1: 69 return 70 if self.own_fd: 71 self.close (self) 72 else: 73 self.flush() 74 os.close(self.child_fd) 75 self.child_fd = -1 76 self.closed = True 77 78 def isalive (self): 79 80 """This checks if the file descriptor is still valid. If os.fstat() 81 does not raise an exception then we assume it is alive. """ 82 83 if self.child_fd == -1: 84 return False 85 try: 86 os.fstat(self.child_fd) 87 return True 88 except: 89 return False 90 91 def terminate (self, force=False): 92 93 raise ExceptionPexpect ('This method is not valid for file descriptors.') 94 95 def kill (self, sig): 96 97 return 98 99
