Synching text files.
abo at minkirri.apana.org.au
Thu Oct 23 11:15:31 EST 2003
On Thu, 2003-10-23 at 05:39, Kurt Roeckx wrote:
> On Wed, Oct 22, 2003 at 11:46:22AM -0700, jw schultz wrote:
> > On Wed, Oct 22, 2003 at 08:31:12PM +0200, Kurt Roeckx wrote:
> > > Hi,
> > >
> > > I'm trying to sync text files where lines get inserted and
> > > deleted. From what I understand, rsync uses blocks to compare
> > > and so can't find much data that matches.
> > >
> > > Would it be possible to make it work so it finds blocks that get
> > > inserted or deleted?
> > It already does.
> Does it only do it on block basis? Or will it try to find an
> offset inside the block?
It will find matching blocks at arbitrary byte offsets.
Think of the original file as a sequence of fixed sized blocks.
Inserting or deleting a single byte "breaks" that block so it no longer
matches, but rsync will match all the blocks before and after that
Note that one think that can break rsync for text files is MSDOS CR/LF
vs Unix LF line termination. This effectively makes a change every line,
and unless you have lines longer than the block size you are using,
rsync will not be able to find a single match.
Donovan Baarda <abo at minkirri.apana.org.au>
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