Search or replace with regular expressions

Regular expressions (or regexes) are wonderful, and you should know how to use them. Vim, as is custom among regex implementations, has its own flavor of regex. However, once you learn one, you're comfortable with all of them.

First, let's talk about the regular (that is, the normal) search and replace command.

Search and replace

Vim supports search and replace through the :substitute command, most often abbreviated to :s. By default, :s will replace one substring with another in a current line. It has the following format:

:s/<find-this>/<replace-with-this>/<flags>

The flags are optional, and you shouldn't worry about them for now. To try it, open...