On Fri, 20 Feb 2009, Duncan Coutts wrote:
I have complained before about the System.Directory file permissions API, and how it relates to copyFile.
Let me give an example of where the existing copyFile API is too limited. Perhaps this will help us think about what an improved API might be.
...
So for Unix the mapping is:
setUserReadable True/False chmod u+r / u-r setUserWritable True/False chmod u+w / u-w
setOtherReadable True/False chmod go+r / go-r setOtherWritable True/False chmod go+w / go-w
It's not hard to predict that 'Other' will be too coarse for some applications, although I haven't an example. However, maybe we should have a new package which provides common functions for Unix and Windows as needed by Cabal. I expect that the 3 cases of permission transfer that you described for Cabal will also occur in other applications. From this package a general API for System.Directory may evolve.