File: desktop.el.html

Save the Desktop, i.e.,
- some global variables
- the list of buffers with associated files. For each buffer also
- the major mode
- the default directory
- the point
- the mark & mark-active
- buffer-read-only
- some local variables
- frame and window configuration

To use this, use customize to turn on desktop-save-mode or add the following line somewhere in your init file:

(desktop-save-mode 1)

For further usage information, look at the section
(info "(emacs)Saving Emacs Sessions") in the GNU Emacs Manual.

When the desktop module is loaded, the function desktop-kill is added to the kill-emacs-query-functions. This function is responsible for saving the desktop and deleting the desktop lock file when Emacs is killed. In addition, an anonymous function is added to the after-init-hook. This function is responsible for loading the desktop when Emacs is started.

Special handling.
-----------------
Variables desktop-buffer-mode-handlers and desktop-minor-mode-handlers are supplied to handle special major and minor modes respectively. desktop-buffer-mode-handlers is an alist of major mode specific functions to restore a desktop buffer. Elements must have the form

   (MAJOR-MODE . RESTORE-BUFFER-FUNCTION).

Functions listed are called by desktop-create-buffer when desktop-read evaluates the desktop file. Buffers with a major mode not specified here, are restored by the default handler desktop-restore-file-buffer. desktop-minor-mode-handlers is an alist of functions to restore non-standard minor modes. Elements must have the form

   (MINOR-MODE . RESTORE-FUNCTION).

Functions are called by desktop-create-buffer to restore minor modes. Minor modes not specified here, are restored by the standard minor mode function. If you write a module that defines a major or minor mode that needs a special handler, then place code like

   (defun foo-restore-desktop-buffer
   ...
   (add-to-list 'desktop-buffer-mode-handlers
                '(foo-mode . foo-restore-desktop-buffer))

or

   (defun bar-desktop-restore
   ...
   (add-to-list 'desktop-minor-mode-handlers
                '(bar-mode . bar-desktop-restore))

in the module itself. The mode function must either be autoloaded, or of the form "foobar-mode" and defined in library "foobar", so that desktop can guess how to load its definition. See the docstrings of desktop-buffer-mode-handlers and desktop-minor-mode-handlers for more info.

Minor modes.
------------
Conventional minor modes (see node "Minor Mode Conventions" in the elisp manual) are handled in the following way: When desktop-save(var)/desktop-save(fun) saves the state of a buffer to the desktop file, it saves as desktop-minor-modes the list of names of those variables in minor-mode-alist that have a non-nil value. When desktop-create restores the buffer, each of the symbols in desktop-minor-modes is called as function with parameter 1. The variables desktop-minor-mode-table and desktop-minor-mode-handlers are used to handle non-conventional minor modes. desktop-save(var)/desktop-save(fun) uses desktop-minor-mode-table to map minor mode variables to minor mode functions before writing desktop-minor-modes. If a minor mode has a variable name that is different form its function name, an entry

   (NAME RESTORE-FUNCTION)

should be added to desktop-minor-mode-table. If a minor mode should not be restored, RESTORE-FUNCTION should be set to nil. desktop-create uses desktop-minor-mode-handlers to lookup minor modes that needs a restore function different from the usual minor mode function.
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By the way: don't use desktop.el to customize Emacs -- the file .emacs in your home directory is used for that. Saving global default values for buffers is an example of misuse.

PLEASE NOTE: The kill ring can be saved as specified by the variable desktop-globals-to-save (by default it isn't). This may result in saving things you did not mean to keep. Use M-x desktop-clear RET.

Thanks to hetrick@phys.uva.nl (Jim Hetrick) for useful ideas.
           avk@rtsg.mot.com (Andrew V. Klein) for a dired tip.
           chris@tecc.co.uk (Chris Boucher) for a mark tip.
           f89-kam@nada.kth.se (Klas Mellbourn) for a mh-e tip.
           kifer@cs.stonybrook.edu (M. Kifer) for a bug hunt.
           treese@lcs.mit.edu (Win Treese) for ange-ftp tips.
           pot@cnuce.cnr.it (Francesco Potortì) for misc. tips.
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TODO:

Recognize more minor modes. Save mark rings.

Defined variables (44)

Defined functions (42)

Defined faces (0)