This looks like god stuff... I wrote a program that backs up selected directories. But it checks if the current file has been backed up before, and if so, it checks if the file to be backed up is newer than the one that had been backed up previously.
But this has a GUI and all kinds of other options available so I hardly ever use it myself, I made it for my computer-n00b father. I'm going to check out rsync me thinks...
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