Vim tip 29: greedy quantifiers

Quantifiers can be applied to literal characters, dot metacharacter, groups, backreferences and character classes.

* match zero or more times
- abc* matches ab or abc or abccc or abcccccc but not bc
- Error.*valid matches Error: invalid input but not valid Error
- s/a.*b/X/ replaces table bottle bus with tXus since a.*b matches from the first a to the last b
\+ match one or more times
- abc\+ matches abc or abccc but not ab or bc
\? match zero or one times
- \= can also be used, helpful if you are searching backwards with the ? command
- abc\? matches ab or abc. This will match abccc or abcccccc as well, but only the abc portion
- s/abc\?/X/ replaces abcc with Xc
\{m,n} match m to n times (inclusive)
- ab\{1,4}c matches abc or abbc or xabbbcz but not ac or abbbbbc
\{m,} match at least m times
- ab\{3,}c matches xabbbcz or abbbbbc but not ac or abc or abbc
\{,n} match up to n times (including 0 times)
- ab\{,2}c matches abc or ac or abbc but not xabbbcz or abbbbbc
\{n} match exactly n times
- ab\{3}c matches xabbbcz but not abbc or abbbbbc

Greedy quantifiers will consume as much as possible, provided the overall pattern is also matched. That's how the Error.*valid example worked. If .* had consumed everything after Error, there wouldn't be any more characters to try to match valid. How the regexp engine handles matching varying amount of characters depends on the implementation details (backtracking, NFA, etc).

info See :h pattern-overview for more details.

info If you are familiar with other regular expression flavors like Perl, Python, etc, you'd be surprised by the use of \ in the above examples. If you use \v very magic modifier, the \ won't be needed.

Video demo: