Dear All, I'm currently working on a project that needs to collect the output of the JHOVE application. More information about the application is available at this website:
http://hul.harvard.edu/jhove/ The application is written in Java and is executed by a shell script. There are occasions where this application may get stuck in an infinite loop. For this reason I've been trying to implement a simple class that I can use to execute the JHOVE application and if it doesn't complete in the required period of time to raise an exception and kill the process. The class is as follows, apologies for the odd line wrapping. <snip> class niceSubprocess(object): """ A class that implements a call to the subprocess method with a timeout - command, the command to execute - params, the parameters to pass to the application - timeout, the amount of time in seconds to wait """ def executeCommand(self, command, params, timeout): try: timeElapsed = 0 process = subprocess.Popen((command, params), stdin = subprocess.PIPE, stdout = subprocess.PIPE, stderr = subprocess.PIPE, close_fds = True) while process.poll() == None and timeElapsed < timeout: print process.poll() #print process.stdout.read() timeElapsed = timeElapsed + 1 time.sleep(1) if process.poll() == None: # kill off the process, and don't be terribly nice about it os.kill(process.pid, signal.SIGKILL) raise timeoutError, timeout else: if process.stdout.read() == "": raise executeError, process.stderr.read() else: return process.stdout.read() except Exception, errorInfo: # pass the exception to the calling code raise errorInfo </snip> I'm running this on Linux and through the use of top can see the JAVA process start and complete. The problem I have is that process.poll() always returns None, even though the application has successfully ran and returned output. Can anyone shed some light on why the call to the shell script always returns None as a return code? With thanks. -Corey -- Corey Wallis RUBRIC Technical Officer University of Southern Queensland http://www.rubric.edu.au http://techxplorer.wordpress.com -- http://mail.python.org/mailman/listinfo/python-list
