Vim regex backreference

Question

I want to do this:

%s/shop_(*)/shop_\1 wp_\1/ 

Why doesn't shop_(*) match anything?

Answer 1

Here are a few questions.

• parens in vim regexen is not meant to be captured - you need to use \( \) for captures.

• * does not mean what you think. This means “0 or more previous”, so your regular expression means “a string containing shop_ followed by 0 + ( and then a literal ) .
  You are looking for . , which in regex means "any character". Comparable to a star as .* , This means "0 or more of any character." You probably need at least one character, so use .\+ ( + Means "1 or more of the previous")

Use this: %s/shop_\(.\+\)/shop_\1 wp_\1/ .

Optionally terminate it with g after the last slash to replace all instances on the same line, not just the first.

Answer 2

If I understand correctly, you want %s/shop_\(.*\)/shop_\1 wp_\1/

Exit the copied bracket and use .* To match any number of characters.

(Your search searches for "shop_", followed by any number of opening parentheses, followed by a closing bracket)