How to quickly change variable names in Vim?

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 {}.

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

Now you have to record a macros 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 simply should enter new_variable_name and press Enter.