- User guide
- Why use CTRLF?
However, you may install using any other package manager if you prefer.
To enable CTRLF, simply add to your init-file:
Note that the autoloading has been configured so that enabling
ctrlf-mode will not actually load CTRLF until you use one of its
Now the usual Isearch bindings will use CTRLF instead:
See Customization to customize the default and alternative search styles.
The design philosophy of CTRLF is to:
- replicate the user experience that users expect from text search based on widespread implementations of ctrl+F functionality
- re-use the flow and keybindings of Isearch
- emphasize reliability and consistency
As such, if you are familiar with Isearch then you will probably be at home in CTRLF.
First you must start a search using one of the following keybindings:
C-s: Search forward for a literal string.
C-r: Search backward for a literal string.
C-M-s: Search forward for a regexp.
C-M-r: Search backward for a regexp.
M-s _: Search forward for a symbol.
M-s .: Search forward for the symbol at point.
During a search, the following core keybindings are available:
C-s: Move to next match. With prefix argument, also convert a regexp search back to a literal search. If there is no search query, insert the previous one, as if you had typed
M-p. This allows you to resume a search with
C-r: Move to previous match. With prefix argument, also convert a regexp search back to a literal search. If there is no search query, insert the previous one, as if you had typed
M-p. This allows you to resume a search with
C-M-s: Move to next match and convert a literal search to a regexp search.
C-M-r: Move to previous match and convert a literal search to a regexp search.
RET: Finish search, leaving point at the currently selected match.
C-g: Abort search, returning point to its original location.
The following additional keybindings are available, emulating standard Emacs bindings:
M-<: Move to first match.
M->: Move to last match.
C-v: Move to first match that appears below the currently visible part of the buffer. In other words, move down by a page.
M-v: Move to first match that appears above the currently visible part of the buffer. In other words, move up by a page.
C-l: Scroll so that the currently selected match is at the center of the window. Typing
C-lmultiple successive times, or providing a prefix argument, has the same effect as usual (see the docstring of the
CTRLF behavior toggles use the same bindings as in Isearch:
M-s c: Toggle case-sensitive search. By default, search is case-sensitive only if your search contains uppercase letters, like in Isearch (following the logic in
M-s s: Change the search style, e.g. between literal, regexp, symbol, fuzzy, or fuzzy-regexp. Search styles are explained thoroughly later in this documentation. There is no equivalent to this in Isearch, but the binding should feel familiar.
M-s r: Toggle between regexp and literal search style.
M-s _: Toggle between symbol and literal search style.
M-s .: Change the search input to the symbol at point, and change the search style to symbol.
M-s o: Open an Occur buffer with the existing search input.
Other than this, keybindings are completely standard. For example, to
delete the last word in your search query, use
M-DEL, or to retrieve
the previous search query in the minibuffer history, use
It is standard in Emacs for typing
M-n after entering the minibuffer
to insert a default value into the minibuffer. In CTRLF, this default
value is the symbol at point.
You can customize the search styles of CTRLF:
- User option
ctrlf-default-search-stylespecifies the default search style (default:
C-sby default) and
C-rby default) use.
- Similarly, user option
ctrlf-alternate-search-stylespecifies the alternative search style (default:
C-M-sby default) and
You can customize the visual appearance of CTRLF:
ctrlf-highlight-activeis used to highlight the currently selected match.
ctrlf-highlight-passiveis used to highlight the other currently visible matches.
ctrlf-highlight-lineis used to highlight the entire line on which the currently selected match resides, if
ctrlf-highlight-current-lineis non-nil (the default).
ctrlf-auto-recenteris non-nil, then the currently selected match is always kept vertically centered in the window, as if you typed
C-leach time you moved to a new match. This feature is disabled by default.
- The index of the currently selected match and the total number of
matches are displayed at the end of the minibuffer (using face
ctrlf-show-match-count-at-eolis non-nil (the default), then this information is also shown at the end of the current line in the buffer being searched (using face
ctrlf-in-buffer-message-face), which alleviates the problem of needing to look back and forth between the minibuffer and the buffer being searched. Both of the mentioned faces inherit from
ctrlf-message-face, as will future faces used by CTRLF to display messages.
- Zero-length matches (for example, in a regexp search for
^$which would identify all blank lines the buffer) are displayed as thin vertical rectangles with a solid color since there is no text to highlight. The width of these rectangles relative to the width of a normal character is defined by
You can also customize the keybindings:
ctrlf-mode-maplists keybindings that are made globally available in Emacs when
ctrlf-minibuffer-mode-maplists keybindings that are made available in the minibuffer during a CTRLF search session.
In addition to the functions already bound in
ctrlf-minibuffer-mode-map, you can choose to bind
ctrlf-previous-match. These functions are the same as
ctrlf-backward, but they do not have the special
features of inserting the previous search, changing to a literal
search, or starting a new search when not already in a search session.
You can customize the behavior:
ctrlf-go-to-end-of-matchis nil, then the cursor will move to the beginning of the match instead of the end.
CTRLF implements support for literal and regexp using an extensible
search style system. This functionality is configured using the
ctrlf-style-alist user option. End users need not touch this option
unless they wish to do advanced customization or are developing a
package which integrates with CTRLF.
The keys of
ctrlf-style-alist define the available search styles.
These styles appear in two places:
- As options in the
ctrlf-change-search-stylecommand bound by default to
- As possible values for the
STYLEargument to the
Basically, a search style defines a way to transform the user's search
query into a regexp which can be passed to
search-backward-regexp. Here are the built-in search styles:
literal: Search for an exact match to the query string, subject to case folding (
C-o c). This is implemented using
regexp: Search for a regexp provided by the user. If the regexp is invalid, CTRLF will display an error message in the minibuffer until the problem is corrected.
fuzzy: Split the query string on spaces and search for an occurrence of all the sub-parts separated by arbitrary text. To include a literal space, or more than one, simply add an additional space. For example,
foo $42 baz quuxis turned into
fuzzy-regexp: Same as
fuzzyexcept that the individual sub-parts are interpreted directly as regexps, so that
foo $42 baz quuxis turned into
To define a custom search style, you should proceed according to the following steps:
- Add an entry to
- The name of the search style as a symbol.
- The string to display in the prompt when using this search
- A function that will take the user input and return a regexp
- A function that will take the user input and guess whether case-folding should be enabled by default.
- Define wrapper functions after the fashion of
ctrlf-backward, respectively, as subroutines.
- Bind these functions in
Disabling CTRLF locally
ctrlf-mode is a globalized minor mode that enables the buffer-local
ctrlf-local-mode. This makes it possible to disable it
when there is a conflict, for example with
(add-hook 'pdf-isearch-minor-mode-hook (lambda () (ctrlf-local-mode -1)))
The minibuffer history for CTRLF is stored in the variable
ctrlf-search-history. You can access it during a search session
M-n at the beginning of a session will
perform a search for the symbol at point. Furthermore, typing
C-r without any search query is a synonym for
CTRLF integrates with evil-mode's jump-list and search history
features. You will be able to jump with
C-i and continue a
N based on your CTRLF searches.
Why use CTRLF?
This section documents why I decided to write CTRLF instead of using any of the numerous existing solutions in Emacs.
Why not Isearch?
Isearch has the right idea for buffer search, but it has serious
usability problems. The main issue, for me, is that it feels extremely
fragile. If you type any command that is not bound in Isearch, then
you exit your search and run that command. This means editing your
search query is awkward and unintuitive. Another issue is
predictability. The behavior of
C-g is hard to predict because it
depends on not only what you have typed in what order, but also on the
buffer contents and the state of the current search. The handling of
wraparound exacerbates problems of predictability: the number of times
you must type
C-s to move to the next match is unpredictable and
the minibuffer prompt changes in several different and confusing ways
during this process.
CTRLF takes the basic idea of Isearch, together with most of its
keybindings, but emulates the more reliable user experience of web
browser text search. For example: all editing commands can be used
during a search as usual;
C-g always has the effect of canceling the
C-s always moves to the next candidate, with wraparound
signaled by an overlay which indicates the current match index and the
total number of matches (another UI paradigm borrowed from other
Why not Swiper?
The selling point of Swiper is that it shows you an overview of the matches. Ask yourself: when was the last time you actually got anything useful out of that overview? Since all the matches are crammed together, one per line, there is not enough context for meaningful information to be communicated. Furthermore, Swiper constrains itself almost exclusively to line-based search by design, which makes it unsuitable to the task of quick movement within a line or movement to a commonly occurring search string.
Why not helm-swoop?
For basically the same reason that Swiper is not a good solution, with
the added complaint that Helm is extraordinarily complex and
in-your-face about this complexity. Single-buffer text search is not a
terribly difficult problem, and given that CTRLF is only about 1,100
lines of code, I think that the 1,700 lines of code of
plus the 10,600 that come with Helm is a bit overkill.
M-x occur implements noninteractive search, and therefore
unsuitable as a tool for quickly jumping to other parts of the buffer.
Why not Avy?
It does not usefully support text search outside the currently visible window.
Please see the contributor guide for my projects.