On 25.10.2004, at 23:11, Geo Carncross wrote:
This is nonsense. The problem is that the behavior of readdir() is confusing.
Why should unlink() or rename() invalidate data that your C library ALREADY READ from the directory?
Why do you think it was already read? It wasn't. That's the problem. An existing renamed file may never be returned by one opendir() .. readdir() .. closedir() loop.
if (stat(d->d_name, &sb) == -1)continue;After your check for the "." in the first character of the d->d_name (about line 41) and all will be good. No amount of twiddling with USE_UNLINK or FILES is going to affect it.
Right. Because the stat() always fails so the whole thing does nothing. If you actually do the correct check:
sprintf(path, PATH"/%s", d->d_name);
if (stat(path, &sb) < 0)
continue;Then it's just as broken as before, but works more slowly.
Of course. For readdir() to be atomic, it would need to do a system call for each directory entry. This is exactly why readdir() doesn't, so that you do one syscall for every (say) 50 entries, and if you want validity, you'll do a stat() yourself.
I don't have a problem with readdir() returning a file that doesn't exist anymore. I have a problem of readdir() not returning an existing file. The exact opposite.
Now: Maildir quite obviously wasn't designed with IMAP in mind. IMAP has some (largely ridiculous) requirements that Maildir simply doesn't make easy.
UIDs mostly.
The largest problem (with Maildir) is this renaming of file identifiers and moving things in and out of cur/. It's only necessary so programs don't have to open() in order to read flags (after all, they JUST did a readdir())...
Out of cur/? open() to read flags? I don't understand.
Since the names aren't going to change in cur/, you can get away with just doing a stat() in there [[ after all, you just rename()'d it into cur/ if you're working on new ]]
Unfortunately, cur/ is often bigger than new/.
Are you trying to say that files wouldn't be allowed to be renamed inside cur/ to change their flags?