54. Hyperlinking and Navigation Features

Various modes documented elsewhere have hypertext features so that you can follow links, usually by clicking Mouse-2 on the link or typing RET while point is on the link. Clicking Mouse-1 quickly on the link also follows it. (Hold Mouse-1 for longer if you want to set point instead.)

Info mode, Help mode and the Dired-like modes are examples of modes that have links in the buffer. The Tags facility links between uses and definitions in source files, see Tags Tables. Imenu provides navigation amongst items indexed in the current buffer, see Imenu. Info-lookup provides mode-specific lookup of definitions in Info indexes, see Documentation Lookup. Speedbar maintains a frame in which links to files, and locations in files are displayed, see Speedbar Frames.

Other non-mode-specific facilities described in this section enable following links from the current buffer in a context-sensitive fashion.

54.1 Following URLs

M-x browse-url RET url RET

Load a URL into a Web browser.

The Browse-URL package provides facilities for following URLs specifying links on the World Wide Web. Usually this works by invoking a web browser, but you can, for instance, arrange to invoke compose-mail from `mailto:' URLs.

The general way to use this feature is to type M-x browse-url, which displays a specified URL. If point is located near a plausible URL, that URL is used as the default. Other commands are available which you might like to bind to keys, such as browse-url-at-point and browse-url-at-mouse.

You can customize Browse-URL's behavior via various options in the browse-url Customize group, particularly browse-url-browser-function. You can invoke actions dependent on the type of URL by defining browse-url-browser-function as an association list. The package's commentary available via C-h p under the `hypermedia' keyword provides more information. Packages with facilities for following URLs should always go through Browse-URL, so that the customization options for Browse-URL will affect all browsing in Emacs.

54.2 Activating URLs

M-x goto-address

Activate URLs and e-mail addresses in the current buffer.

You can make URLs in the current buffer active with M-x goto-address. This finds all the URLs in the buffer, and establishes bindings for Mouse-2 and C-c RET on them. After activation, if you click on a URL with Mouse-2, or move to a URL and type C-c RET, that will display the web page that the URL specifies. For a `mailto' URL, it sends mail instead, using your selected mail-composition method (see section Mail-Composition Methods).

It can be useful to add goto-address to mode hooks and the hooks used to display an incoming message. rmail-show-message-hook is the appropriate hook for Rmail, and mh-show-mode-hook for MH-E. This is not needed for Gnus, which has a similar feature of its own.

54.3 Finding Files and URLs at Point

FFAP mode replaces certain key bindings for finding files, including C-x C-f, with commands that provide more sensitive defaults. These commands behave like the ordinary ones when given a prefix argument. Otherwise, they get the default file name or URL from the text around point. If what is found in the buffer has the form of a URL rather than a file name, the commands use browse-url to view it.

This feature is useful for following references in mail or news buffers, `README' files, `MANIFEST' files, and so on. The `ffap' package's commentary available via C-h p under the `files' keyword and the ffap Custom group provide details.

You can turn on FFAP minor mode by calling ffap-bindings to make the following key bindings and to install hooks for using ffap in Rmail, Gnus and VM article buffers.

C-x C-f filename RET

Find filename, guessing a default from text around point (find-file-at-point).

C-x C-r

ffap-read-only, analogous to find-file-read-only.

C-x C-v

ffap-alternate-file, analogous to find-alternate-file.

C-x d directory RET

Start Dired on directory, defaulting to the directory name at point (dired-at-point).

C-x C-d

ffap-list-directory, analogous to list-directory.

C-x 4 f

ffap-other-window, analogous to find-file-other-window.

C-x 4 r

ffap-read-only-other-window, analogous to find-file-read-only-other-window.

C-x 4 d

ffap-dired-other-window, analogous to dired-other-window.

C-x 5 f

ffap-other-frame, analogous to find-file-other-frame.

C-x 5 r

ffap-read-only-other-frame, analogous to find-file-read-only-other-frame.

C-x 5 d

ffap-dired-other-frame, analogous to dired-other-frame.

M-x ffap-next

Search buffer for next file name or URL, then find that file or URL.

S-Mouse-3

ffap-at-mouse finds the file guessed from text around the position of a mouse click.

C-S-Mouse-3

Display a menu of files and URLs mentioned in current buffer, then find the one you select (ffap-menu).

This document was generated by Mark Kaminski on July, 3 2008 using texi2html 1.70.