Hi all, I found this blogpost from Bryan O'Sullivan http://www.serpentine.com/blog/2008/09/30/unix-hacking-in-haskell-better-pse... and I wanted to try it out. Before moving to an interactive command (which needs pty), I just did a small test for "ls -l /" to see if it worked. I got it to compile, but when running, it throws an exception when reaching the end of the output (in this case because I evaluate the length to force reading all). Main: /dev/ptmx: hGetContents: hardware fault (Input/output error) Please have a look at the hpaste to see what I did: http://hpaste.org/fastcgi/hpaste.fcgi/view?id=23343 What's wrong? :) My guess is that hGetContents doesn't receive a nice EOF when the process exits (ls doesn't stay around waiting for input), but I have no idea on how to fix this. And further... If I do want to use an interactive program which needs input, how do I send ctrl-d or ctrl-c? tail -f needs ctrl-c (or I need to kill the process) Thanks for any help Mathijs PS: I know about libexpect, it's not useful for what I wanna do (multiple processes, having 'answers' from 1 be used to decide what to input the other, without ending the 'answer' process)