How can you change the case of a backreference in Ex-mode substitute command?

Question

For instance, let's say I want to change all instances of Ctrl-m, Ctrl-p, etc., in a document to the more conventional ^M, ^P, etc. I can use :s/Ctrl-\(.\)/^\1to almost accomplish this, but it leaves the letters in lowercase where they should be in uppercase.

How can I change the case of a backreferenced regex match in a Ex-mode substitute command? (:s)

Answer 1

Perhaps like this:

:%s/Ctrl-\(.\)/^\u\1/g

For more information: :help s/\u.