Calling an external command from a Haskell program

[Simon Marlow]

> I've cc-ed to the libraries list - perhaps someone there could
> comment on the state of portable replacements for Posix
> functionality, especially for popen and friends? I seem to
> recall a very promising discussion about portable and flexible
> ways to start subprocesses a while ago - has that led to any
> concrete libraries?

Regarding processes, I made this proposal:

  http://www.haskell.org/pipermail/libraries/2003-May/000958.html

but didn't get any further.  The sticking point is that GHC needs a
thread-safe wait() implementation, which means some hacking in the
scheduler (there isn't even a good way to do this portably, because
select() doesn't let you wait for process termination).

Cheers,
	Simon