Harishankar <[EMAIL PROTECTED]> wrote: > Sorry to start off on a negative note in the list, but I feel that the > Python > subprocess module is sorely deficient because it lacks a mechanism to: > > 1. Create non-blocking pipes which can be read in a separate thread (I am > currently writing a mencoder GUI in Tkinter and need a full fledged process > handler to control the command line and to display the progress in a > text-box) > > 2. Kill the subprocess in a platform independent manner (i.e. no third party > modules and no hacks).
You are correct on both of those points. Subprocess isn't for interacting with subprocesses - this should be written in large letters in the help! > Is there any way to use non-blocking Popen objects using > subprocess? There is a recipe in the cookbook http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/440554 Which I've used and it works. you can also (if on unix) use http://www.noah.org/wiki/Pexpect I think the best solution would be to port Pexpect to windows which wouldn't be that difficult according to my reading of the code. If only I had more free time! > and 2 - is there a way to kill the subprocess in a platform > independent manner in a purely Pythonic way? I thought initially > that this problem is simple enough, but over the last couple of > days I've been really struggling to find any answer. I've been > through dozens of mailing list archives in to find a > solution. Unfortunately none of the solutions seem to fit my needs. No... This is the best I came up with to add to the subprocess recipe above import os from subprocess import * from subprocess import mswindows from time import sleep if mswindows: import win32api else: import signal class PopenNB(Popen): # - see cookbook recipe for rest of stuff # ... def kill(self, killpg=False): """ Kill the running process """ pid = self.pid if mswindows: # Kill the process using win32api and pid - ignore errors try: PROCESS_TERMINATE = 1 handle = win32api.OpenProcess(PROCESS_TERMINATE, False, pid) win32api.TerminateProcess(handle, -1) win32api.CloseHandle(handle) except pywintypes.error: pass else: # Kill the process by sending the pid / process group a signal if killpg: try: pgid = os.getpgid(pid) except OSError: killpg = False try: if killpg: os.killpg(pgid, signal.SIGTERM) else: os.kill(pid, signal.SIGTERM) except OSError: return sleep(1.0) try: if killpg: os.killpg(pgid, signal.SIGKILL) else: os.kill(pid, signal.SIGKILL) except OSError: return -- Nick Craig-Wood <[EMAIL PROTECTED]> -- http://www.craig-wood.com/nick -- http://mail.python.org/mailman/listinfo/python-list
