[ale] One home directory

[William Fragakis]

I'm just a newbie but wouldn't the -u flag take care of clobbering a
newer version of the same file?

-u, --update
              This  forces rsync to skip any files which exist on the
destina-
              tion and have a modified time that  is  newer  than  the
source
              file.   (If an existing destination file has a
modification time
              equal to the source file’s, it will be updated if the
sizes  are
              different.)


wf

On Wed, 2009-10-14 at 21:35 -0400, Brian Pitts wrote:
> On 10/14/2009 09:02 AM, Jeff Lightner wrote:
> > It won't delete things unless you tell it to.
> 
> True.
> 
> >  One hopes that someone
> > that is using the same file on two separate systems isn't updating it
> > independently on each as that is the only time it would "clobber" the
> > file on one side or the other.
> 
> Not true. Look at my example again; I've left it below. File b is only
> updated on one system, but it is clobbered. Rsync doesn't care that the
> version of b on the target is newer than the version on the source. It
> checks if the file on the target has a different size or timestamp than
> the file on the source, sees that it does, and alters it to match the
> source version.
> 
> THis is why you can't accomplish a bidirectional sync by "run[ning] two
> separate rsync jobs - one that used one side as the source and the other
> as the target and another that used the original source as target and
> original target as source." After the first rsync, you've clobbered any
> newer files on the original target. There's nothing for the second rsync
> to do!
> 
> >   If one IS updating it on each side
> > independently I doubt there is any tool that would reasonably decided
> > which version is the one you want - at best it would decided based on
> > which one had last been updated.
> 
> True, but unison handles this nicely by offering to show you a diff and
> let you choose which version you want or to skip syncing it so you can
> resolve things manually.
> 
> > 
> > $ mkdir one two
> > $ touch one/a one/b
> > $ rsync -av one/ two/
> > sending incremental file list
> > ./
> > a
> > b
> > 
> > sent 138 bytes  received 53 bytes  382.00 bytes/sec
> > total size is 0  speedup is 0.00
> > $ ls -l one two
> > one:
> > total 0
> > -rw-rw-r-- 1 brian brian 0 2009-10-13 20:07 a
> > -rw-rw-r-- 1 brian brian 0 2009-10-13 20:07 b
> > 
> > two:
> > total 0
> > -rw-rw-r-- 1 brian brian 0 2009-10-13 20:07 a
> > -rw-rw-r-- 1 brian brian 0 2009-10-13 20:07 b
> > $ echo one > one/a
> > $ echo two > two/b
> > $ ls -l one two
> > one:
> > total 4
> > -rw-rw-r-- 1 brian brian 4 2009-10-13 20:07 a
> > -rw-rw-r-- 1 brian brian 0 2009-10-13 20:07 b
> > 
> > two:
> > total 4
> > -rw-rw-r-- 1 brian brian 0 2009-10-13 20:07 a
> > -rw-rw-r-- 1 brian brian 4 2009-10-13 20:07 b
> > $ cat two/b
> > two
> > $ rsync -av one/ two/
> > sending incremental file list
> > a
> > b
> > 
> > sent 151 bytes  received 50 bytes  402.00 bytes/sec
> > total size is 4  speedup is 0.02
> > $ cat two/b
> > $
> > 
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