It's called 'raw' because it is supposed to get the arguments through *unmodified* to the called program. No file globbing, no escape stuff, nothing.
That's exactly what I'm worried about: it seems that rawSystem is *not* passing the arguments unmodified, but tries to compensate for windows interpretation, from a unix perspective (*).
No, the effect is that the arguments are passed unmodified to the program. The implementation of rawSystem might have to do some compensation under the hood (eg. on Windows), but that's not visible to the client.
As long as "raw" means "unmodified", I just have the problem of finding the appropriate documentation for the system I'm working on (after all, that's why it's in System). But if there are two interpreters fighting with each other for some unstable balance, things do not look so promising.
For instance, I can't use rawSystem in ghc-6.x because there are already two different versions in circulation, and a third one planned. So, instead of simplifying my code, I'd have to triplicate it, and add version testing, which adds preprocessing..
This is an unfortunate situation, granted. ghc-6.0.x had a version of rawSystem that was not very raw: on Windows there was a layer of translation between rawSystem and the invoked program, and on Unix it didn't even allow you to pass any arguments to the program. We thought this was wrong, and decided to make rawSystem truly raw. Unfortunately we got it slightly wrong in 6.2. 6.2.1 will be better (I hope), and in the meantime we can offer an implementation of rawSystem that you can use locally to work around the differences - how does that sound?
Therefore, my suggestion would be to keep the rawSystem from ghc-6.0.1 (which doesn't seem to do any interpretation?), and to provide a system-specific escape function
System.Cmd.escape :: String -> String -> String -- (System.Cmd.escape chars string) escapes occurrences of -- chars in string, according to convention on the current -- system
If really necessary, there could be a convenience function somewhat like:
-- try to do "the right thing" System.Cmd.rawSystem' :: String -> [String] -> IO ExitCode System.Cmd.rawSystem' path args = rawSystem $ concat (path:[' ':(escape "\\\"" a) | a <- args])
I don't think it's necessary to do any of this, if rawSystem works as it's intended. But I may have misunderstood your intention... Cheers, Simon