Re: Proposal: overhaul System.Process

On Fri, May 23, 2008 at 08:22:56PM +0100, Duncan Coutts wrote:

On Fri, 2008-05-16 at 15:44 +0100, Brian Brunswick wrote:

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On Thu, May 15, 2008 at 10:45 AM, Simon Marlow wrote:

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The latest version of the Process overhaul is here:

- changes to readProcess, and added readProcessWithExitCode, as discussed on the list.

I'd just like to argue briefly again against merging stdout and stderr.

I think I agree. A more sensible default would be to discard stdout completely or to use the inherited stderr. Though exactly which depends on the context unfortunately.

For Cabal we have a function like readProcess and it discards stderr. This seems to be the right thing for the various uses in Cabal (except stupid "python -V" which prints the version number to stderr).

I'd vote for inherited stderr instead, as otherwise it can be very hard for users (or developers!) to debug what goes wrong with an external command. -- David Roundy Department of Physics Oregon State University