Regexp

The helm-regexp command is Helm’s version of the built-in RE-Builder (re-builder), which highlights matches in the buffer and provides instant feedback as you write a regexp.

By default, helm-regexp is bound to <helm-prefix> r; it can also be found in the menu bar under Tools > Helm > Tools > Regexp handler.

Features

helm-regexp has several features. A comparison with re-builder highlights differences between the two.

helm-regexp	re-builder
Write regexp without double backslashes, and copy with/without them.	Manually switch between syntaxes with C-c TAB (reb-change-syntax).
View all matches in a list, and navigate with standard Helm commands.	Use C-c C-s (reb-next-match) or C-c C-r (reb-prev-match) to navigate between matches in the target buffer.
View numbered capturing groups for each match.	Capturing groups are highlighted in different colors.
Call query-replace-regexp directly with Helm action.	N/A