Behavior of --checksum, suggestion

[Moshe Jacobson]

Hi rsync folks,

I understand that by default, rsync will re-copy a file if the
timestamp differs, but the size is the same.

Sometimes, though, I have large files whose mtime have been changed
but are otherwise identical.  It seems a solution to this is
--checksum, but it seems like --checksum computes the checksum for ALL
files, which is time consuming.

What would be nice is if we could have a --checksum=ifneeded, which
would compute the checksum of two files only when their size is the
same but the mtime differs.  If the files turned out to have the same
checksum, the destination's mtime would simply be updated without the
whole file being re-transferred.

Is this something that would be hard to implement?

Thanks,
Moshe

-- 
Moshe Jacobson -- http://runslinux.net -- AIM: Jehsom
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