Question

I am using Vim to read through a lot of C and Perl code containing many single letter variable names.

It would be nice to have some command to change the name of a variable to something more meaningful while I’m in the process of reading the code, so that I could read the rest of it faster.

Is there some command in Vim which could let me do this quickly?

I don’t think regexes would work because:

1. the same single letter name might have different purposes in different scoping blocks; and

2. the same combination of letters could be part of another longer variable name, a string literal, or a comment.

Are there any known solutions?

Answer 1

The following is how to rename a variable which is defined in the current scope {}.

1. Move your cursor to the variable usage.
2. Press gd. Which means – move the cursor to the definition.
3. Now Press [{ – this will bring you to the scope begin.
4. Press V – will turn on Visual Line selection.
5. Press % – will jump to the opposite } and thus will select the whole scope.
6. Press :s/ – start of the substitute command.
7. <C-R>/ – will insert a pattern that matches the variable name (that name you were on before pressing gd).
8. /newname/gc<CR> – will initiate search and replace with confirmation on every match.

Now you have to record a macro or even better – map a key.

Here are the final mappings:

" For local replace nnoremap gr gd[{V%::s/<C-R>///gc<left><left><left>  " For global replace nnoremap gR gD:%s/<C-R>///gc<left><left><left> 

Put this to your .vimrc or just execute. After this pressing gr on the local variable will bring you to :s command where you should enter new_variable_name and press Enter.