* Nobody <nob...@nowhere.com> [130830 06:55]: > On Thu, 29 Aug 2013 17:00:21 -0800, Tim Johnson wrote: > > > ## This appears to be what works. > > def __exec(self,args) : > > """Run the process with arguments""" > > p = > > subprocess.Popen(args,stderr=subprocess.PIPE,stdout=subprocess.PIPE) > > while 1 : > > output = p.stdout.read() > > If the process tries to write more than a pipe's worth of data to stderr, > before closing stdout, it will block indefinitely. > > If you want to process both stdout and stderr, you have to be able to > consume the data in whatever order the process generates it, which means > either using multiple threads or (on Unix) select/poll or non-blocking > I/O. This is what the .communicate() method does (threads on Windows, > select/poll on Unix). > > The alternative is to merge both streams with stderr=subprocess.STDOUT, or > redirect one of them to a file (or /dev/null, etc). In earlier code I, I was merging them... :) Like I said: gnarly! What if I were to do something like: ## code while 1: output = p.stout.read() err = p.stderr.read() ## trapping for AttributeError, etc.. .... ## /code break'ing if either no output or value in `err' ?? The objective is to display all output, but to also separate error messages from normal output.
thank you -- Tim tim at tee jay forty nine dot com or akwebsoft dot com http://www.akwebsoft.com -- http://mail.python.org/mailman/listinfo/python-list