Vim regexesEdit
Basics
\1, \2 etc: backreference to previous capturing group (works in both search pattern and replacement)&: backreference the entire match (same as \0)
Gotchas
* is special when not escaped but…+ is special when escaped\{x,y} (escaping only the opening bracket) works but…- You have to use
\( \) (escape both parens)
[] is special when both are unescaped
Pro-Tips
\v: everything is special unless escaped ("very magic")\V: turn off very-magic- You can use (somewhat) arbitrary delimiters, like
@, instead of /
\_: match anything, including newlines (cf: .)\zs: consider match to start at this point (ie. match but don’t capture); useful for partial substitutions:\ze: consider match to end at this point
:%s/foo\zsbar/baz/g will change "foobar" to "foobaz":%s/\v^(foobar)(baz)/\1/ (same with explicit capturing and restoration):%s/\v(^foobar)@<=baz// (same with zero-width look-behind assertion)
\=: evaluate an expression on right side of regex; eg: :%s/\v(\S+)/\=expand(submatch(1))/g (turns ~/foo into full path)\C: make match case sensitive\u: uppercase next letter in replacement\l: lowercase next letter in replacement\U: uppercase replacement from here on (until \e or \E)\L: lowercase replacement from here on (until \e or \E)
Making Vim regexen more sane
\1, \2 etc: backreference to previous capturing group (works in both search pattern and replacement)&: backreference the entire match (same as \0)*is special when not escaped but…+is special when escaped\{x,y}(escaping only the opening bracket) works but…- You have to use
\( \)(escape both parens) []is special when both are unescaped
Pro-Tips
\v: everything is special unless escaped ("very magic")\V: turn off very-magic- You can use (somewhat) arbitrary delimiters, like
@, instead of /
\_: match anything, including newlines (cf: .)\zs: consider match to start at this point (ie. match but don’t capture); useful for partial substitutions:\ze: consider match to end at this point
:%s/foo\zsbar/baz/g will change "foobar" to "foobaz":%s/\v^(foobar)(baz)/\1/ (same with explicit capturing and restoration):%s/\v(^foobar)@<=baz// (same with zero-width look-behind assertion)
\=: evaluate an expression on right side of regex; eg: :%s/\v(\S+)/\=expand(submatch(1))/g (turns ~/foo into full path)\C: make match case sensitive\u: uppercase next letter in replacement\l: lowercase next letter in replacement\U: uppercase replacement from here on (until \e or \E)\L: lowercase replacement from here on (until \e or \E)
Making Vim regexen more sane
\v: everything is special unless escaped ("very magic")\V: turn off very-magic@, instead of /\_: match anything, including newlines (cf: .)\zs: consider match to start at this point (ie. match but don’t capture); useful for partial substitutions:\ze: consider match to end at this point
:%s/foo\zsbar/baz/gwill change "foobar" to "foobaz":%s/\v^(foobar)(baz)/\1/(same with explicit capturing and restoration):%s/\v(^foobar)@<=baz//(same with zero-width look-behind assertion)
\=: evaluate an expression on right side of regex; eg: :%s/\v(\S+)/\=expand(submatch(1))/g (turns ~/foo into full path)\C: make match case sensitive\u: uppercase next letter in replacement\l: lowercase next letter in replacement\U: uppercase replacement from here on (until \e or \E)\L: lowercase replacement from here on (until \e or \E)Always be "very magic" with this in your ~/.vimrc:
nnoremap / /\v
vnoremap / /\v
Or just use Loupe.
Using Ruby to do heavy lifting instead
:rubydo can be used to transform lines; eg:
:rubydo $_ = $_.split(' ').reverse.join(' <- ')