Find and replace in Vim

22 Dec 2014

Finding and replacing a given string is a pretty basic text editing feature. Vim fulfils this requirement more than adequately but there are a few tricks to learn and remember.

Working in the current buffer

If you are only concerned with a single file in the current buffer then things are fairly straightforward. There are a couple of ways that you can tackle the problem.

The substitute command

You can use the substitute command (or :s for short) to replace one string (or regex) with a different string:

:s/foo/bar/

replaces foo with bar but only operates on the current line and only on the first occurrence of foo so if you want to replace every occurrence of foo what you probably want is:

:%s/foo/bar/g

% effectively means all lines and the g modifier means operate on each occurrence in the given line.

Other useful modifiers are c for confirmation and i for case-insensitive matching, e.g.

:%s/foo/bar/gci

A common requirement is to replace the word under the cursor. To achieve this you can take advantage of the default search expression being the last search expression to avoid retyping, so if you already have the cursor over the word foo hit the * key then:

:%s//bar/g

Change and repeat

If you don’t want to drop into command mode, you can change the first occurrence of the search string, change it manually and then repeat the change. So for example, /foo finds the first foo, ciw lets you replace it and then n. repeats the change on the next match.

You can repeat the change with a single . if you use cgn to replace the next match in one hit (gn finds and selects the next match).

Working across multiple files

I find it a bit more tricky to remember how to find and replace across multiple files. Having to change the name of a class or method across an entire project can make you wish you were working in a big IDE and a statically-typed language.

Vim doesn’t have a built-in project-wide find and replace function but it does have some more flexible tools that make the job simple enough once you know the tricks. The key tool is the arglist combined with the argdo command. The arglist is a list of files that you can populate and argdo will run a command across all of them.

So if you need to populate the arglist with all you JavaScript files:

:args **/*.js

and then replace foo with bar in each of them:

:argdo %s/foo/bar/gce

The e option ignores errors, such as not finding a match in a given file. I’m using the c option so that I can confirm each change manually in this example.

Finally you’ll need to save those files:

:argdo w

This approach works but is a bit of a sledgehammer because we are processing every file that may contain the search string. There is an excellent VimCast discussing a more refined approach and ways in which this may get a little smarter in future versions of Vim.