"Last changed" timestamp is ignored?

[Wayne Davison]

On Fri, Jun 15, 2007 at 03:44:12AM +0930, Carey O'Shea wrote:
> Rsync's "does this file need to be updated" check can conclude "this 
> file does not need updating" even though the "last changed" timestamp 
> differs. This happens when the size and modify timestamp are equal. Why 
> doesn't rsync consider the "last changed" timestamp in the same respect 
> as the modify timestamp? Doesn't changed mean, er, changed?

The modified timestamp is the last-changed timestamp.  If you're
referring to the ctime, that is the time the inode was last changed,
which is something different (and it can stay the same when a file's
data is changed, and can change when a file has unchanged data).  The
only other posix timestamp is last accessed time.

> I noticed this when editing some Ogg Vorbis tags with a tag editing 
> program (Easytag).

That's a shortcoming with easytag, then.  If it modifies a file and sets
the modified timestamp back to its pre-changed value, it is masking the
change.

..wayne..