good ol' rsync

Among other backup strategies for my laptop (including, frankly, moving a lot of important stuff to Dropbox, despite the minor security concerns) I like doing some file syncing "the old fashioned way", manual copies to a plugged in USB drive.

I had to interrupt a copy of my main "~/data/" folder though, and didn't want to take the time to start another full copy, so I googled and was reminded of rsync:

rsync -av /source-path/source-dir/ /other-path/dest-dir/

as the stackechange page I cribbed that from reminds me, assuming you want "dest-dir" to have the same contents as "source-dir" make sure both the old and the new paths keep their trailing slashes, otherwise you might be off by a level.