RE: [Boost-Users] Boost::Filesystem: Directory iterator and dangling links

From: Beman Dawes (bdawes_at_[hidden])
Date: 2003-04-22 19:40:36

At 06:36 AM 4/22/2003, Ben Hutchings wrote:

 >...Is it desirable that links
 >be resolved?  I suppose it is if the iterator is being used to walk
 >a whole tree - but not if it's being used to list a single directory.

Here is the rationale for resolving links: if links are resolved, then 
applications desiring resolution work, and by querying attributes, 
applications not desiring resolution also work.

If links are ignored, then there is no way to for applications desiring 
resolution to work.

 >Perhaps there is a need to include explicit support for links in the
 >API.  Windows has supported them since 2000, so they aren't just a
 >Unix thing now.

Keep in mind that there are two forms of links - the simplest kind acts 
like a pointer, and like a pointer, can fail if the pointed to entry is 
removed.

The other kind of link is more like a reference counted smart pointer, 
where the only way to access the entry is via the link. That provides much 
more disciplined link management, since the actual filesystem object never 
goes away as long as any links are present.

It wouldn't surprise me if there were also some other kinds of links out 
there, with still different behavior.

--Beman