Can I make :s operate only on the last match of the line?

Question

:s/pattern/replacement operates on the first match and :s/pattern/replacement/g on all.

How to operate only on the last one?

Answer 1

I would use \zs

:%s/.*\zspattern/replacement/

A little bit of explanation:

• . represents any single character
• * represents greedy matching (as many as possible)

In Vim you can use zero-width anchors \zs and \ze to define the start and the end of the searched pattern, which you wish to match. Anything before \zs and after \ze in your pattern will remain unaffected by replacement.

To make it easy to understand, I would like to use this example from wikia's Search and replace:

Save typing by using \zs and \ze to set the start and end of a pattern. For example, instead of:

:s/Copyright 2007 All Rights Reserved/Copyright 2008 All Rights Reserved/ 

Use:

:s/Copyright \zs2007\ze All Rights Reserved/2008/

For more information, look at

• :h \zs
• :h pattern-overview

Answer 2

You can search for the last match by grouping all, \(.*\), but last ocurrence of pattern. Then exiting with the captured group, \1, and adding the replacement.

:%s/\(.*\)pattern/\1replacement/

Answer 3

For the sake of completeness I thought I'd post an alternative. Vim has multi-items some of which are similar to the more standard regular expression lookaround assertions (negative/positive lookahead/lookbehind). https://stackoverflow.com/questions/2973436/regex-lookahead-lookbehind-and-atomic-groups

In this case we want a negative lookahead, \@!, meaning we want to assert that the atom that precedes the item does not occur after pattern. In this case the atom is the pattern itself preceded by anything else:

:%s/pattern\(.*pattern\)\@!/replacement/

The part inside the parentheses is zero-width and not included in the match so is not replaced by the substitution.

:h \@! for more information or :h pattern-multi-items for the whole section containing other lookaround variations.