RFD: deprecate permissions-related stuff in System.Directory
Malcolm.Wallace at cs.york.ac.uk
Thu Aug 30 06:14:08 EDT 2007
> > I have a perfectly OK use of getPermissions: in hmake, there is a
> > routine that scans the PATH variable looking for an executable with
> > a given name. Basically, it is a Haskell implementation of the unix
> > 'which' command. There is no actual use of the executable, just a
> > test to report/reject the candidate pathname.
> You wouldn't be losing much by using doesFileExist rather than
But on unix, it would be totally incorrect to return a file of the right
name but with the wrong permissions. This is what my Haskell `which`
originally did, and it bit me hard on a couple of occasions, hence the
> On Windows it turns out to be really hard if not
> impossible to check for execute permission - the only reliable way is
> to actually try to execute the file.
Mounting a FAT filesystem on unix (or indeed any filesystem via Samba)
also makes all files appear to be executable. These are just broken
platforms, and I don't think they should hold us hostage or dictate our
I'm not saying that the current API is perfect - it could certainly be
improved. But I'm just pointing out that there are valid use-cases for
what we have currently. If you have concrete suggestions for a new API,
I would certainly be interested.
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