transfer files only once

[Tony at ServaCorp.com]

Hermann Gausterer wrote:
> 
> hi
> 
> i have a question. is there an easy way to remember transfered
> files to a specific destination host.
> 
> little example: 
> 1) host A: with files a, b, c
> 2) rsync-transfer them to host B
> 3) add a new file d to host A
> 4) delete file c from host B
> 5) again a rsync transfer, but file c get skipped, d get transferred
> 
> maybe as a feature request:
> add an check for an extended attribut of the files which gets
> set if a file is the first time transfered and get skipped if
> the attribut is set.
> 
> or is it possible to move all transfered files directly in an
> rsync exclude file; would have the same effect
> 
> i hope somebody understand what i want ;-)
> 
> mfg hermann
> 
Further, I can see two possibilities that should be distinguished:
when file c is updated on host A:
plan A: transfer the updated file c to host B
plan B: do not transfer the file c (updated or no) to host B

With anything but rsync I'd guess your chances are between slim and none.

Leaving a zero-length unwritable file with the same name would achieve
some of the objectives (but is ugly even compared to what I usually do)