Re: [boost] BUG: filesystem remove_all [PATCH]

From: Beman Dawes (bdawes_at_[hidden])
Date: 2005-01-19 19:08:49

At 10:58 PM 1/18/2005, Walter Landry wrote:
 >Greetings,
 >
 >I have discovered a bug in the implementation of remove_all.
 >remove_all works by reading through a directory and deleting entries
 >along the way.  If it comes across a subdirectory, it immediately
 >recurses into that subdirectory.  However, boost::filesystem uses
 >readdir, which on some platforms (including OS X, apparently) uses a
 >static data area that can be overwritten on each call to readdir.
 >This messes up the original directory iteration, ending up with some
 >entries not being deleted.
 >
 >A solution is to not recurse the directory immediately, but to make a
 >list of them.  Once you have gone through all of the entries in a
 >directory, then you recurse into the subdirectories.  A patch is
 >below, although it could probably be improved.

Walter,

Thanks for the report. As Peter pointed out, that isn't supposed to happen 
on a POSIX compliant system. Is it possible the bug is actually in the 
remove_all code or your code?

I've had a "to do" item for a month or so to change readdir to readdir_r on 
systems which support it. My guess is that almost all modern POSIX 
operating systems support readdir_r, but there is a configuration macro so 
the code can adapt to what is available. I'm not sure my guesses about 
POSIX are worth anything, however, since I would have guessed every modern 
POSIX OS implements readdir correctly:-( Anyhow, readdir_r should solve 
this problem so I'll accelerate that fix.

--Beman