Proposal: overhaul System.Process

Simon Marlow marlowsd at
Tue Apr 22 19:25:14 EDT 2008

Duncan Coutts wrote:
> On Tue, 2008-04-22 at 15:45 -0700, Simon Marlow wrote:
>>> What happens to stderr with this function, by the way?
>>>  Is it tied to stdout (probably the right thing to do), or to /dev/null,
>>> or is it closed (eek!)?  
>> None of the above :)  Currently it's inherited from the parent. 
>> Unfortunately it's not easy to tie stderr and stdout to the same pipe - 
>> createProcess can't do that, and readProcess is defined in terms of it.
> I don't understand the restriction. What if we just pass stdout as the
> handle to use for stdout and stderr. The types say that's possible, so
> what would go wrong?

Yes that's possible, but what you can't do is create a new pipe and 
attach both stdout and stderr to it.


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