Loccur

Introduction

Loccur is an amazing tool to quickly navigate in a file. It is a minor mode for Emacs acting like occur but w/o creating a new window. It just hides all the text excepting lines containing matches.

Installation

Add to your .emacs or .emacs.d/init.el following lines:

(setq package-archives '(("gnu" . "http://elpa.gnu.org/packages/")
                         ("melpa" . "http://melpa.milkbox.net/packages/")))

Press M-x in GNU Emacs and write list-packages. Find the loccur in the list of packages and press i to select this package, x to install the package.

Screenshots

Better to see it once:

Usage

To use it, add the following to your .emacs file:

(require 'loccur)
;; defines shortcut for loccur of the current word
(define-key global-map [(control o)] 'loccur-current)
;; defines shortcut for the interactive loccur command
(define-key global-map [(control meta o)] 'loccur)
;; defines shortcut for the loccur of the previously found word
(define-key global-map [(control shift o)] 'loccur-previous-match)

Now you can point the cursor to the word and press Ctrl+o to hide all lines except those containing this word. Moving cursor to the required line and pressing Ctrl+o again will shows all the text. The good thing about this mode is what you can navigate through the buffer easily. Ctrl+Shift+o will repeat last search.

Available commands

Below is the list of interactive commands available for user:

loccur interactively asks user for regexp to search or toggle search off (if loccur-mode is already enabled)
loccur-current searches for the current word under the cursor
loccur-previous-match repeat previous loccur command
loccur-no-highlight is the same as loccur but not highlighting matches
loccur-toggle-highlight toggles highlighting of matches
loccur-isearch: incremental occur (more details below)

Customization

loccur-jump-beginning-of-line variable specifies if move the cursor to the beginning of the matching line. Default nil
loccur-highlight-matching-regexp variable whenever loccur should highlight matching words. Default t.
loccur-face face to be used while highlighting. Default points to isearch face.

Isearch integration

The loccur-isearch command filters buffer lines incrementally as you type a search string. It can also be called when Isearch is already active to turn filtering on or off. For the latter functionality, you should bind the command in isearch-mode-map, for example as follows:

(define-key global-map (kbd "M-s C-o") 'loccur-isearch)
(define-key isearch-mode-map (kbd "C-o") 'loccur-isearch)

astoff/loccur