This is elisp, produced by makeinfo version 4.0f from ./elisp.texi. INFO-DIR-SECTION Editors START-INFO-DIR-ENTRY * Elisp: (elisp). The Emacs Lisp Reference Manual. END-INFO-DIR-ENTRY This Info file contains edition 2.8 of the GNU Emacs Lisp Reference Manual, corresponding to Emacs version 21.2. Published by the Free Software Foundation 59 Temple Place, Suite 330 Boston, MA 02111-1307 USA Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with the Invariant Sections being "Copying", with the Front-Cover texts being "A GNU Manual", and with the Back-Cover Texts as in (a) below. A copy of the license is included in the section entitled "GNU Free Documentation License". (a) The FSF's Back-Cover Text is: "You have freedom to copy and modify this GNU Manual, like GNU software. Copies published by the Free Software Foundation raise funds for GNU development."  File: elisp, Node: Special Keysyms, Next: Flow Control, Prev: Sound Output, Up: System Interface System-Specific X11 Keysyms =========================== To define system-specific X11 keysyms, set the variable `system-key-alist'. - Variable: system-key-alist This variable's value should be an alist with one element for each system-specific keysym. Each element has the form `(CODE . SYMBOL)', where CODE is the numeric keysym code (not including the "vendor specific" bit, -2**28), and SYMBOL is the name for the function key. For example `(168 . mute-acute)' defines a system-specific key (used by HP X servers) whose numeric code is -2**28 + 168. It is not crucial to exclude from the alist the keysyms of other X servers; those do no harm, as long as they don't conflict with the ones used by the X server actually in use. The variable is always local to the current terminal, and cannot be buffer-local. *Note Multiple Displays::.  File: elisp, Node: Flow Control, Next: Batch Mode, Prev: Special Keysyms, Up: System Interface Flow Control ============ This section attempts to answer the question "Why does Emacs use flow-control characters in its command character set?" For a second view on this issue, read the comments on flow control in the `emacs/INSTALL' file from the distribution; for help with Termcap entries and DEC terminal concentrators, see `emacs/etc/TERMS'. At one time, most terminals did not need flow control, and none used `C-s' and `C-q' for flow control. Therefore, the choice of `C-s' and `C-q' as command characters for searching and quoting was natural and uncontroversial. With so many commands needing key assignments, of course we assigned meanings to nearly all ASCII control characters. Later, some terminals were introduced which required these characters for flow control. They were not very good terminals for full-screen editing, so Emacs maintainers ignored them. In later years, flow control with `C-s' and `C-q' became widespread among terminals, but by this time it was usually an option. And the majority of Emacs users, who can turn flow control off, did not want to switch to less mnemonic key bindings for the sake of flow control. So which usage is "right"--Emacs's or that of some terminal and concentrator manufacturers? This question has no simple answer. One reason why we are reluctant to cater to the problems caused by `C-s' and `C-q' is that they are gratuitous. There are other techniques (albeit less common in practice) for flow control that preserve transparency of the character stream. Note also that their use for flow control is not an official standard. Interestingly, on the model 33 teletype with a paper tape punch (around 1970), `C-s' and `C-q' were sent by the computer to turn the punch on and off! As window systems and PC terminal emulators replace character-only terminals, the flow control problem is gradually disappearing. For the mean time, Emacs provides a convenient way of enabling flow control if you want it: call the function `enable-flow-control'. - Command: enable-flow-control This function enables use of `C-s' and `C-q' for output flow control, and provides the characters `C-\' and `C-^' as aliases for them using `keyboard-translate-table' (*note Translating Input::). You can use the function `enable-flow-control-on' in your init file to enable flow control automatically on certain terminal types. - Function: enable-flow-control-on &rest termtypes This function enables flow control, and the aliases `C-\' and `C-^', if the terminal type is one of TERMTYPES. For example: (enable-flow-control-on "vt200" "vt300" "vt101" "vt131") Here is how `enable-flow-control' does its job: 1. It sets CBREAK mode for terminal input, and tells the operating system to handle flow control, with `(set-input-mode nil t)'. 2. It sets up `keyboard-translate-table' to translate `C-\' and `C-^' into `C-s' and `C-q'. Except at its very lowest level, Emacs never knows that the characters typed were anything but `C-s' and `C-q', so you can in effect type them as `C-\' and `C-^' even when they are input for other commands. *Note Translating Input::. If the terminal is the source of the flow control characters, then once you enable kernel flow control handling, you probably can make do with less padding than normal for that terminal. You can reduce the amount of padding by customizing the Termcap entry. You can also reduce it by setting `baud-rate' to a smaller value so that Emacs uses a smaller speed when calculating the padding needed. *Note Terminal Output::.  File: elisp, Node: Batch Mode, Prev: Flow Control, Up: System Interface Batch Mode ========== The command-line option `-batch' causes Emacs to run noninteractively. In this mode, Emacs does not read commands from the terminal, it does not alter the terminal modes, and it does not expect to be outputting to an erasable screen. The idea is that you specify Lisp programs to run; when they are finished, Emacs should exit. The way to specify the programs to run is with `-l FILE', which loads the library named FILE, and `-f FUNCTION', which calls FUNCTION with no arguments. Any Lisp program output that would normally go to the echo area, either using `message', or using `prin1', etc., with `t' as the stream, goes instead to Emacs's standard error descriptor when in batch mode. Similarly, input that would normally come from the minibuffer is read from the standard input descriptor. Thus, Emacs behaves much like a noninteractive application program. (The echo area output that Emacs itself normally generates, such as command echoing, is suppressed entirely.) - Variable: noninteractive This variable is non-`nil' when Emacs is running in batch mode.  File: elisp, Node: Antinews, Next: GNU Free Documentation License, Prev: System Interface, Up: Top Emacs 20 Antinews ***************** For those users who live backwards in time, here is information about downgrading to Emacs version 20.4. We hope you will enjoy the greater simplicity that results from the absence of many Emacs 21 features. In the following section, we carry this information back to Emacs 20.3, for which the previous printed edition of this manual was made. Old Lisp Features in Emacs 20 ============================= * The `push' and `pop' macros are not defined. Neither are `dolist' and `dotimes'. * You can't display images in buffers. (Emacs is meant for editing text.) With no images, there are no display margins, and no tool bars. * The `display' text property has no special meaning; you can use it freely in Lisp programs, with no effects except what you implement for yourself. With no images, who needs the `display' text property? * The `field' text property has no special meaning; buffers are no longer subdivided into fields. (The division of information into fields is always rather arbitrary.) * Faces have fewer attributes. The attributes `:family', `:height', `:width', `:weight', and `:slant', have been replaced with a font name, a "bold" flag, and an "italic" flag. The attributes `:overline', `:strike-through' and `:box' have been eliminated too. Underlining now always has the same color as the text--using any other color would be bad taste. With fewer font attributes, there are no functions `set-face-attribute' and `face-attribute'. Instead, you access these attributes using functions such as `face-font', and set them with functions such as `set-face-font'. (These functions were available in Emacs 21, but are not as useful there.) * The standard faces `scroll-bar', `menu', `border', `cursor', and `mouse' have been eliminated. They are rather strange, as faces, and therefore shouldn't really exist. You can use `set-border-color', `set-cursor-color' and `set-mouse-color' to specify the colors for the frame border, the text cursor, and the mouse cursor. To specify menu colors, use X resources. * Colors and other face attributes are no longer supported on character terminals, so you no longer have to worry about terminals making faces at you. * Emacs will respect your peace and quiet, aside from occasional beeps, because there are no facilities for playing sounds. * Emacs 20 provides a complex and badly designed method for handling character composition for languages such as Thai that display several letters as a single combined image. We are too ashamed of it to tell you any more than that. * `delete-and-extract-region' has been deleted; instead, use `buffer-substring' to extract the text, then use `delete-region' to delete it. * Regular expressions do not support the POSIX character classes such as `[:alpha:]'. All characters are created equal. * Hash tables have been eliminated; use alists instead. * The Lisp printer does not detect and report circular structure. That is ok, because the Lisp reader cannot recreate circular structure anyway. However, there is a library `cust-print.el' which can report circular structure. * Emacs provides its own implementation of scroll bars, instead of using those of the X toolkit. They always use the frame foreground and background colors, so you cannot specify different colors for the scroll bars. * For simplicity, all ASCII characters now have the same height and width. (Certain characters, such as Chinese characters, always have twice the standard width.) All characters are created equal. * You can now resize any Emacs window, and size changes in one window can propagate to all others. Windows can no longer use `window-size-fixed' to get special privileges. * The function `intern-soft' no longer accepts a symbol as argument. * The function `bitmap-spec-p' has been renamed to `pixmap-spec-p' to encourage users to practice Emacs' help system while trying to find it. * Tooltips operate using ordinary Emacs frames. * Areas of the mode line are not mouse-sensitive; however, some mouse commands are available for the mode line as a whole. * Windows cannot have header lines. Conversely, there is no way to turn off the mode line of a window unless it is a minibuffer. * Plain dashes are the only separators you can use in a menu. * Vertical fractional scrolling does not exist. * The functions `format' and `message' ignore and discard text properties. * The function `propertize' does not exist; you can get the job done using `set-text-properties'. * Colors are supported only on window systems, not on text-only terminals. So the support functions for colors on text-only terminals are not needed, and have been eliminated. * The functions `color-values', `color-defined-p' and `defined-colors' have been renamed to `x-color-values', `x-color-defined-p' and `x-defined-colors'. * Windows cannot be made fixed-width or fixed-height; Emacs will adjust the size of all windows when it needs to. * The string used as the value of the `before-string' or `after-string' property must contain only characters that display as a single column--control characters, including tabs and newlines, will give strange results. * The minibuffer prompt does not actually appear in content of the minibuffer; it is displayed specially in the minibuffer window. * The "exclusive open" feature of `write-region' has been eliminated; any non-`nil' value for the seventh argument now means to ask the user for confirmation. * The function `buffer-size' always reports on the current buffer. * The function `assq-delete-all' has itself been deleted. So there! * The keyword `:set-after' no longer does anything in `defcustom'. * The variable `small-temporary-file-directory' has no special meaning. There's only one variable for specifying which directory to use for temporary files, `temporary-file-directory', but not all Emacs features use it anyway. Some use the `TMP' environment variable, and some use the `TMPDIR' environment variable. * If the second argument of `save-some-buffers', PRED, is not `nil', then the precise value no longer matters. Any non-`nil' value means the same as `t': offer to save each non-file buffer that has a non-`nil' value for `buffer-offer-save'. * The variable `inhibit-modification-hooks' has no special meaning. * The hook `fontification-functions' has been eliminated, but there are other hooks, such as `window-scroll-functions', that you can use to do a similar job. * The variable `redisplay-dont-pause' has no special meaning. * The hook `calendar-move-hook' has been deleted. * The function `move-to-column' treats any non-`nil' second argument just like `t'. Old Lisp Features in Emacs 20.3 =============================== Here are the most important of the features that you will learn to do without in Emacs 20.3: Here are changes in the Lisp language itself: * The functions `line-beginning-position' and `line-end-position' have been eliminated. * The functions `directory-files-and-attributes', `file-attributes-lessp', and `file-expand-wildcards', have been eliminated. * The functions `decode-coding-region' and `encode-coding-region' leave text properties untouched, in case that is useful. (It rarely makes any sense, though.) * The functions `position-bytes' and `byte-to-position' have been eliminated. * Temporary buffers made with `with-output-to-temp-buffer' are now modifiable by default, and use Fundamental mode rather than Help mode. * The functions `sref' interprets its INDEX argument as a number of bytes, not a number of characters. And the function `char-bytes' actually tries to report on the number of bytes that a character occupies. * The function `process-running-child-p' has been eliminated. * The function `interrupt-process' and similar functions no longer do anything special when the second argument is `lambda'. * The function `define-prefix-command' accepts only two arguments. * The meaning of the second argument to `read-char', `read-event', and `read-char-exclusive' has been reversed: they use the current input method if the argument is if `nil'. * The function `with-temp-message' has been eliminated. * The function `clear-this-command-keys' has been eliminated. * The functions `gap-position' and `gap-size' have been eliminated. * In `modify-face', an argument of `(nil)' has no special meaning. * The base64 conversion functions have been eliminated. * Wildcard support has been eliminated from `find-file' and allied functions. * `file-attributes' returns the file size and the file inode number only as a simple integer.  File: elisp, Node: GNU Free Documentation License, Next: GPL, Prev: Antinews, Up: Top GNU Free Documentation License ****************************** Version 1.1, March 2000 Copyright (C) 2000 Free Software Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. 0. PREAMBLE The purpose of this License is to make a manual, textbook, or other written document "free" in the sense of freedom: to assure everyone the effective freedom to copy and redistribute it, with or without modifying it, either commercially or noncommercially. Secondarily, this License preserves for the author and publisher a way to get credit for their work, while not being considered responsible for modifications made by others. This License is a kind of "copyleft", which means that derivative works of the document must themselves be free in the same sense. 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Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with the Invariant Sections being LIST THEIR TITLES, with the Front-Cover Texts being LIST, and with the Back-Cover Texts being LIST. A copy of the license is included in the section entitled ``GNU Free Documentation License''. If you have no Invariant Sections, write "with no Invariant Sections" instead of saying which ones are invariant. If you have no Front-Cover Texts, write "no Front-Cover Texts" instead of "Front-Cover Texts being LIST"; likewise for Back-Cover Texts. If your document contains nontrivial examples of program code, we recommend releasing these examples in parallel under your choice of free software license, such as the GNU General Public License, to permit their use in free software.