emacs-iedit Edit multiple regions in the same way simultaneously

This package is an Emacs minor mode and allows you to edit one occurrence of some text in a buffer (possibly narrowed) or region, and simultaneously have other occurrences edited in the same way.

You can also use Iedit mode as a quick way to temporarily show only the buffer lines that match the current text being edited. This gives you the effect of a temporary keep-lines or occur.