Thanks MRAB, > > You need to ensure that the pipe is already open at the other end.
So I need to open the process that reads the pipe before writing in it? > > > > Why are you using a named pipe anyway? For some bug in ipython (see my previous email) I can't use subprocess.Popen and pipe in the standard way. One of Ipython developers has suggested me to use named pipes as a temporary workaround. So I am taking the occasion to learn :) > > If you're talking to another program, then that needs to be running > > already, waiting for the connection, at the point that you open the > > named pipe from this end. I am not entirely sure I got this: ideally I would like to have a function that runs an external tool (the equivalent of ls in my example) redirecting its output in a named pipe. A second function (the cat command in my example) would read the named_pipe, parse it and extract some features from the output. I also would like that the named_pipe is deleted when the whole communication is ended. > > If you're using a pipe _within_ a program (a queue would be better), > > then you should opening for writing in one thread and for reading in > > another. Let's stick with the pipe :) I will ask about the queue when I manage to use pipes ;) I should have explained better that I have no idea how to run threads in Python :): how do I open a thread that executes "ls -lah" in background and writes into a named pipe? And how do I open a thread that reads from the named pipe? Can you please post a small example, so that I have something to work on? Thanks a lot in advance for your help! Luca -- http://mail.python.org/mailman/listinfo/python-list
