Remove everything except regex match in Vim

by

This effect can be accomplished by using sub-replace-special substitution and setreg() linewise

:let @a=""
:%s//\=setreg('A', submatch(0), 'l')/g
:%d _
:pu a
:0d _

or all in one line as such:

:let @a=""|%s//\=setreg('A', submatch(0), 'l')/g|%d _|pu a|0d _

Overview: Using a substitution to append each match into register “a” linewise then replace the entire buffer with the contents of register “a”

Explanation:

  1. let @a="" empty the “a” register that we will be appending into
  2. %s//\=setreg('A', submatch(0), 'l')/g substitute globally using the last pattern
  3. the \=expr will replace the pattern with the contents of the expression
  4. submatch(0) get the entire string of what just matched
  5. setreg('A', submatch(0), 'l') append (note: the capital “a”) to @a the matched string, but linewise
  6. %d _ delete every line into the black hole register (aka @_)
  7. pu a put the contents of @a into the buffer
  8. 0d _ delete the first line

Concerns:

  • This will trash one of your registers. This example trashed @a
  • Uses the last search pattern. Although you can modify the substitute command with whatever pattern you want: %s/<pattern>/\=setreg('A', submatch(0), 'l')/g

For more help

:h :s\=
:h :let-@
:h submatch()
:h setreg()
:h :d
:h :p

More Related Contents:

  1. How can I make my match non greedy in vim?
  2. How does one escape backslashes and forward slashes in VIM find/search?
  3. How to search and replace with a counter-based expression in Vim?
  4. How to get Vim to highlight non-ascii characters?
  5. Why does VIM have its own regex syntax?
  6. Can I substitute multiple items in a single regular expression in VIM or Perl?
  7. Match parenthesised block using regular expressions in vim
  8. Greedy vs. Reluctant vs. Possessive Qualifiers
  9. RegEx: Grabbing values between quotation marks
  10. Regular Expression to match valid dates
  11. In regex, match either the end of the string or a specific character
  12. How to match numbers between X and Y with regexp?
  13. Regex for Comma delimited list
  14. What’s the regular expression that matches a square bracket?
  15. Can you make just part of a regex case-insensitive?
  16. How does the regular expression ‘(?
  17. Regex AND operator
  18. Oracle 11g get all matched occurrences by a regular expression
  19. Regex number between 1 and 100
  20. Short example of regular expression converted to a state machine?
  21. Unix grep regex containing ‘x’ but not containing ‘y’
  22. What regular expression can never match?
  23. is there something akin to regEx in applescript, and if not, what’s the alternative?
  24. Regular Expression Validation For Indian Phone Number and Mobile number
  25. htaccess force https and redirect www to non-www, but no other subdomains
  26. Filtering a diff with a regular expression
  27. Design DFA accepting binary strings divisible by a number ‘n’
  28. Regex matching beginning AND end strings
  29. Regex return file name, remove path and file extension
  30. Matching url with array list of words in AngularJS ui-router

Leave a Comment