Multiple cursors for Emacs. This is some pretty crazy functionality, so yes, there are kinks. Don't be afraid tho, I've been using it since 2011 with great success and much merriment.

Basic usage

Start out with:

(require 'multiple-cursors)

Then you have to set up your keybindings - multiple-cursors doesn't presume to know how you'd like them laid out. Here are some examples:

When you have an active region that spans multiple lines, the following will add a cursor to each line:

(global-set-key (kbd "C-S-c C-S-c") 'mc/edit-lines)

When you want to add multiple cursors not based on continuous lines, but based on keywords in the buffer, use:

(global-set-key (kbd "C->") 'mc/mark-next-like-this)
(global-set-key (kbd "C-<") 'mc/mark-previous-like-this)
(global-set-key (kbd "C-c C-<") 'mc/mark-all-like-this)

First mark the word, then add more cursors.

To get out of multiple-cursors-mode, press <return> or C-g. The latter will first disable multiple regions before disabling multiple cursors. If you want to insert a newline in multiple-cursors-mode, use C-j.

Video

You can watch an intro to multiple-cursors at Emacs Rocks.

Command overview

Mark one more occurrence

mc/mark-next-like-this: Adds a cursor and region at the next part of the buffer forwards that matches the current region.
mc/mark-next-word-like-this: Like mc/mark-next-like-this but only for whole words.
mc/mark-next-symbol-like-this: Like mc/mark-next-like-this but only for whole symbols.
mc/mark-previous-like-this: Adds a cursor and region at the next part of the buffer backwards that matches the current region.
mc/mark-previous-word-like-this: Like mc/mark-previous-like-this but only for whole words.
mc/mark-previous-symbol-like-this: Like mc/mark-previous-like-this but only for whole symbols.
mc/mark-more-like-this-extended: Use arrow keys to quickly mark/skip next/previous occurances.

Mark many occurrences

mc/mark-all-like-this: Marks all parts of the buffer that matches the current region.
mc/mark-all-words-like-this: Like mc/mark-all-like-this but only for whole words.
mc/mark-all-symbols-like-this: Like mc/mark-all-like-this but only for whole symbols.
mc/mark-all-in-region: Prompts for a string to match in the region, adding cursors to all of them.
mc/mark-all-like-this-in-defun: Marks all parts of the current defun that matches the current region.
mc/mark-all-words-like-this-in-defun: Like mc/mark-all-like-this-in-defun but only for whole words.
mc/mark-all-symbols-like-this-in-defun: Like mc/mark-all-like-this-in-defun but only for whole symbols.
mc/mark-all-like-this-dwim: Tries to be smart about marking everything you want. Can be pressed multiple times.

Special

set-rectangular-region-anchor: Think of this one as set-mark except you're marking a rectangular region.
mc/mark-sgml-tag-pair: Mark the current opening and closing tag.

Tips and tricks

To get out of multiple-cursors-mode, press <return> or C-g. The latter will first disable multiple regions before disabling multiple cursors. If you want to insert a newline in multiple-cursors-mode, use C-j.
Sometimes you end up with cursors outside of your view. You can scroll the screen to center on each cursor with C-v and M-v.
Try pressing mc/mark-next-like-this with no region selected. It will just add a cursor on the next line.
Try pressing mc/mark-all-like-this-dwim on a tagname in html-mode.
Notice that the number of cursors active can be seen in the modeline.
If you would like to keep the global bindings clean, and get custom keybindings when the region is active, you can try region-bindings-mode.

BTW, I highly recommend adding mc/mark-next-like-this to a key binding that's right next to the key for er/expand-region.

Unknown commands

Multiple-cursors uses two lists of commands to know what to do: the run-once list and the run-for-all list. It comes with a set of defaults, but it would be beyond silly to try and include all the known Emacs commands.

So that's why multiple-cursors occasionally asks what to do about a command. It will then remember your choice by saving it in ~/.emacs.d/.mc-lists.el. You can change the location with:

(setq mc/list-file "/my/preferred/file")

Known limitations

isearch-forward and isearch-backward aren't supported with multiple cursors. You should feel free to add a simplified version that can work with it.
Commands run with M-x won't be repeated for all cursors.
All key bindings that refer to lambdas are always run for all cursors. If you need to limit it, you will have to give it a name.
Redo might screw with your cursors. Undo works very well.

Contribute

Yes, please do. There's a suite of tests, so remember to add tests for your specific feature, or I might break it later.

You'll find the repo at:

https://github.com/magnars/multiple-cursors.el

To fetch the test dependencies:

$ cd /path/to/multiple-cursors
$ git submodule update --init

Run the tests with:

$ ./util/ecukes/ecukes --graphical

Contributors

Takafumi Arakaki made .mc-lists.el diff friendly
Marco Baringer contributed looping to mc/cycle and adding cursors without region for mark-more.
Ivan Andrus added showing number of cursors in mode-line
Fuco added the first version of mc/mark-all-like-this-dwim

Thanks!

License

Author: Magnar Sveen magnars@gmail.com Keywords: editing cursors

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.