Question

I would like to find a good way in Vim to do this search and replace for the following –

name_1
end
name_2
end

name_3
end

where I take name_”x” and append it to it’s following “end” statement. So it would look like this –

name_1
end_name_1
name_2
end_name_2
name_3

end_name_3

Note – the empty line before name_3 ruins a constant line spacing between “name_x” and “end”. So I was thinking of something like

:g/\(name_x\)/,/end/ s/end/end_\1/

Now that doesn’t work trying to store the first pattern like that but hopefully you get the idea. Any tricks here?

Thanks

Answer 1

The issue you are having is that \1 refers to the current substitution’s match group not the :g command’s pattern. Sadly you can not access previous match groups from previous searches. There are however ways to accomplish your goal. The first I would suggest is a macro.

First off start on a a non matching line. This can be done by inserting a blank line at the top of the file if needed (just remove it afterwards).

1. start the macro search for your pattern: /name_\d\+
2. yank until the end of your pattern: y//e
3. find the end pattern: /end/e
4. insert a underscore a_
5. paste with p
6. end your macro q
7. execute the macro with a large number. e.g. 999@q

Here is the macro I used:

:let @q = "/name_\\d\\+\<cr>y//e\<cr>/end/e\<cr>a_\<esc>p"

The other way is to use the :global command in a similar fashion to your attempt.

:g/name_\d\+/let @@=matchstr(getline('.'),'name_\d\+')|/end/s//\=submatch(0).'_'.@@/

I personally this is much too complicated, but it is nice to have options. The command can be broken down into the following parts:

• :g/name_\d\+ execute a command on each line matching name_ and some number
• getline('.') will return a string of the current line
• matchstr(getline('.'), 'name_\d\+') will return only the matching part of the current line
• let @@ = matchstr(...) will set the matched portion to the default register
• /end/s/ will execute a :s on the following line that matches end
• s//\=.../ matches the last used pattern and replaces it with an express.
• submatch(0).'_'.@@ create a string with the whole matched pattern followed by an underscore and the contents of the unnamed register.

For more information on the following topics see:

:h q
:h search-offset
:h :g
:h :let-@
:h registers
:h matchstr(
:h getline(
:h range
:h submatch(