ref: febccadc5c510972572ffbec29a43abacbd9519c dir: /harmful/☭cp/
#!/bin/rc tar c `' '{diff <{lr -dQ $1 | sort} <{cd $2 && lr -dQ $1 | sort} | sed -n '/^< /s/^< //p'} | @{cd $2 && tar xT}