On Thu, Feb 02, 2012 at 09:50:45PM -0700, Philip Guenther wrote: >>> The current man page doesn't claim that errno is always set but one might >>> reasonably assume that it is: certainly, it seems a horribly easy way of >>> introducing bugs (at least for idiots such as myself). [...] [Christiano] >> Although I like your intention, I think the problem is in the later part: >> >> The readdir() and readdir_r() functions may also fail and set errno for >> any of the errors specified for the routine getdirentries(2). >> >> Maybe this could be clarified ? >> >> Lets see what others think. > I'll propose a third option: I think the directory(3) manpage would be > clearer if the DESCRIPTION section was unwoven to have separate DESCRIPTION > and RETURN VALUES section. Explicit wording that errno is not set when end > of directory is reached and that programs that want to tell apart > end-of-directory and errors must set errno to zero should be added.
I think this would make a lot of sense. > I also think readdir() should set errno if it detects an invalid seekdir(). > EINVAL seems correct. This seems like a good idea overall, but I have one minor worry. Does any other Unix do this? If not, it may introduce another subtle portability bug, if a program thinks it can detect an invalid seekdir by checking whether errno was set or not by readdir. This is purely hypothetical though. Laurie -- Personal http://tratt.net/laurie/ The Converge programming language http://convergepl.org/ https://github.com/ltratt http://twitter.com/laurencetratt
