1 This is ../info/xemacs.info, produced by makeinfo version 4.0 from
4 INFO-DIR-SECTION XEmacs Editor
6 * XEmacs: (xemacs). XEmacs Editor.
9 This file documents the XEmacs editor.
11 Copyright (C) 1985, 1986, 1988 Richard M. Stallman. Copyright (C)
12 1991, 1992, 1993, 1994 Lucid, Inc. Copyright (C) 1993, 1994 Sun
13 Microsystems, Inc. Copyright (C) 1995 Amdahl Corporation.
15 Permission is granted to make and distribute verbatim copies of this
16 manual provided the copyright notice and this permission notice are
17 preserved on all copies.
19 Permission is granted to copy and distribute modified versions of
20 this manual under the conditions for verbatim copying, provided also
21 that the sections entitled "The GNU Manifesto", "Distribution" and "GNU
22 General Public License" are included exactly as in the original, and
23 provided that the entire resulting derived work is distributed under the
24 terms of a permission notice identical to this one.
26 Permission is granted to copy and distribute translations of this
27 manual into another language, under the above conditions for modified
28 versions, except that the sections entitled "The GNU Manifesto",
29 "Distribution" and "GNU General Public License" may be included in a
30 translation approved by the author instead of in the original English.
33 File: xemacs.info, Node: File Variables, Prev: Locals, Up: Variables
35 Local Variables in Files
36 ------------------------
38 A file can contain a "local variables list", which specifies the
39 values to use for certain Emacs variables when that file is edited.
40 Visiting the file checks for a local variables list and makes each
41 variable in the list local to the buffer in which the file is visited,
42 with the value specified in the file.
44 A local variables list goes near the end of the file, in the last
45 page. (It is often best to put it on a page by itself.) The local
46 variables list starts with a line containing the string `Local
47 Variables:', and ends with a line containing the string `End:'. In
48 between come the variable names and values, one set per line, as
49 `VARIABLE: VALUE'. The VALUEs are not evaluated; they are used
52 The line which starts the local variables list does not have to say
53 just `Local Variables:'. If there is other text before `Local
54 Variables:', that text is called the "prefix", and if there is other
55 text after, that is called the "suffix". If a prefix or suffix are
56 present, each entry in the local variables list should have the prefix
57 before it and the suffix after it. This includes the `End:' line. The
58 prefix and suffix are included to disguise the local variables list as
59 a comment so the compiler or text formatter will ignore it. If you do
60 not need to disguise the local variables list as a comment in this way,
61 there is no need to include a prefix or a suffix.
63 Two "variable" names are special in a local variables list: a value
64 for the variable `mode' sets the major mode, and a value for the
65 variable `eval' is simply evaluated as an expression and the value is
66 ignored. These are not real variables; setting them in any other
67 context does not have the same effect. If `mode' is used in a local
68 variables list, it should be the first entry in the list.
70 Here is an example of a local variables list:
71 ;;; Local Variables: ***
73 ;;; comment-column:0 ***
74 ;;; comment-start: ";;; " ***
75 ;;; comment-end:"***" ***
78 Note that the prefix is `;;; ' and the suffix is ` ***'. Note also
79 that comments in the file begin with and end with the same strings.
80 Presumably the file contains code in a language which is enough like
81 Lisp for Lisp mode to be useful but in which comments start and end
82 differently. The prefix and suffix are used in the local variables
83 list to make the list look like several lines of comments when the
84 compiler or interpreter for that language reads the file.
86 The start of the local variables list must be no more than 3000
87 characters from the end of the file, and must be in the last page if the
88 file is divided into pages. Otherwise, Emacs will not notice it is
89 there. The purpose is twofold: a stray `Local Variables:' not in the
90 last page does not confuse Emacs, and Emacs never needs to search a
91 long file that contains no page markers and has no local variables list.
93 You may be tempted to turn on Auto Fill mode with a local variable
94 list. That is inappropriate. Whether you use Auto Fill mode or not is
95 a matter of personal taste, not a matter of the contents of particular
96 files. If you want to use Auto Fill, set up major mode hooks with your
97 init file to turn it on (when appropriate) for you alone (*note Init
98 File::). Don't try to use a local variable list that would impose your
99 taste on everyone working with the file.
101 XEmacs allows you to specify local variables in the first line of a
102 file, in addition to specifying them in the `Local Variables' section
103 at the end of a file.
105 If the first line of a file contains two occurrences of ``-*-'',
106 XEmacs uses the information between them to determine what the major
107 mode and variable settings should be. For example, these are all legal:
109 ;;; -*- mode: emacs-lisp -*-
110 ;;; -*- mode: postscript; version-control: never -*-
111 ;;; -*- tags-file-name: "/foo/bar/TAGS" -*-
113 For historical reasons, the syntax ``-*- modename -*-'' is allowed
114 as well; for example, you can use:
116 ;;; -*- emacs-lisp -*-
118 The variable `enable-local-variables' controls the use of local
119 variables lists in files you visit. The value can be `t', `nil', or
120 something else. A value of `t' means local variables lists are obeyed;
121 `nil' means they are ignored; anything else means query.
123 The command `M-x normal-mode' always obeys local variables lists and
124 ignores this variable.
127 File: xemacs.info, Node: Keyboard Macros, Next: Key Bindings, Prev: Variables, Up: Customization
132 A "keyboard macro" is a command defined by the user to abbreviate a
133 sequence of keys. For example, if you discover that you are about to
134 type `C-n C-d' forty times, you can speed your work by defining a
135 keyboard macro to invoke `C-n C-d' and calling it with a repeat count
139 Start defining a keyboard macro (`start-kbd-macro').
142 End the definition of a keyboard macro (`end-kbd-macro').
145 Execute the most recent keyboard macro (`call-last-kbd-macro').
148 Re-execute last keyboard macro, then add more keys to its
152 When this point is reached during macro execution, ask for
153 confirmation (`kbd-macro-query').
155 `M-x name-last-kbd-macro'
156 Give a command name (for the duration of the session) to the most
157 recently defined keyboard macro.
159 `M-x insert-kbd-macro'
160 Insert in the buffer a keyboard macro's definition, as Lisp code.
162 Keyboard macros differ from other Emacs commands in that they are
163 written in the Emacs command language rather than in Lisp. This makes
164 it easier for the novice to write them and makes them more convenient as
165 temporary hacks. However, the Emacs command language is not powerful
166 enough as a programming language to be useful for writing anything
167 general or complex. For such things, Lisp must be used.
169 You define a keyboard macro by executing the commands which are its
170 definition. Put differently, as you are defining a keyboard macro, the
171 definition is being executed for the first time. This way, you see
172 what the effects of your commands are, and don't have to figure them
173 out in your head. When you are finished, the keyboard macro is defined
174 and also has been executed once. You can then execute the same set of
175 commands again by invoking the macro.
179 * Basic Kbd Macro:: Defining and running keyboard macros.
180 * Save Kbd Macro:: Giving keyboard macros names; saving them in files.
181 * Kbd Macro Query:: Keyboard macros that do different things each use.
184 File: xemacs.info, Node: Basic Kbd Macro, Next: Save Kbd Macro, Up: Keyboard Macros
189 To start defining a keyboard macro, type `C-x ('
190 (`start-kbd-macro'). From then on, anything you type continues to be
191 executed, but also becomes part of the definition of the macro. `Def'
192 appears in the mode line to remind you of what is going on. When you
193 are finished, the `C-x )' command (`end-kbd-macro') terminates the
194 definition, without becoming part of it.
200 defines a macro to move forward a word and then insert `foo'.
202 You can give `C-x )' a repeat count as an argument, in which case it
203 repeats the macro that many times right after defining it, but defining
204 the macro counts as the first repetition (since it is executed as you
205 define it). If you give `C-x )' an argument of 4, it executes the
206 macro immediately 3 additional times. An argument of zero to `C-x e'
207 or `C-x )' means repeat the macro indefinitely (until it gets an error
210 Once you have defined a macro, you can invoke it again with the `C-x
211 e' command (`call-last-kbd-macro'). You can give the command a repeat
212 count numeric argument to execute the macro many times.
214 To repeat an operation at regularly spaced places in the text,
215 define a macro and include as part of the macro the commands to move to
216 the next place you want to use it. For example, if you want to change
217 each line, you should position point at the start of a line, and define
218 a macro to change that line and leave point at the start of the next
219 line. Repeating the macro will then operate on successive lines.
221 After you have terminated the definition of a keyboard macro, you
222 can add to the end of its definition by typing `C-u C-x ('. This is
223 equivalent to plain `C-x (' followed by retyping the whole definition
224 so far. As a consequence it re-executes the macro as previously
228 File: xemacs.info, Node: Save Kbd Macro, Next: Kbd Macro Query, Prev: Basic Kbd Macro, Up: Keyboard Macros
230 Naming and Saving Keyboard Macros
231 ---------------------------------
233 To save a keyboard macro for longer than until you define the next
234 one, you must give it a name using `M-x name-last-kbd-macro'. This
235 reads a name as an argument using the minibuffer and defines that name
236 to execute the macro. The macro name is a Lisp symbol, and defining it
237 in this way makes it a valid command name for calling with `M-x' or for
238 binding a key to with `global-set-key' (*note Keymaps::). If you
239 specify a name that has a prior definition other than another keyboard
240 macro, Emacs prints an error message and nothing is changed.
242 Once a macro has a command name, you can save its definition in a
243 file. You can then use it in another editing session. First visit the
244 file you want to save the definition in. Then use the command:
246 M-x insert-kbd-macro <RET> MACRONAME <RET>
248 This inserts some Lisp code that, when executed later, will define the
249 same macro with the same definition it has now. You need not
250 understand Lisp code to do this, because `insert-kbd-macro' writes the
251 Lisp code for you. Then save the file. You can load the file with
252 `load-file' (*note Lisp Libraries::). If the file you save in is your
253 initialization file (*note Init File::), then the macro will be defined
254 each time you run Emacs.
256 If you give `insert-kbd-macro' a prefix argument, it creates
257 additional Lisp code to record the keys (if any) that you have bound to
258 the keyboard macro, so that the macro is reassigned the same keys when
262 File: xemacs.info, Node: Kbd Macro Query, Prev: Save Kbd Macro, Up: Keyboard Macros
264 Executing Macros With Variations
265 --------------------------------
267 You can use `C-x q' (`kbd-macro-query'), to get an effect similar to
268 that of `query-replace'. The macro asks you each time whether to make
269 a change. When you are defining the macro, type `C-x q' at the point
270 where you want the query to occur. During macro definition, the `C-x
271 q' does nothing, but when you invoke the macro, `C-x q' reads a
272 character from the terminal to decide whether to continue.
274 The special answers to a `C-x q' query are <SPC>, <DEL>, `C-d',
275 `C-l', and `C-r'. Any other character terminates execution of the
276 keyboard macro and is then read as a command. <SPC> means to continue.
277 <DEL> means to skip the remainder of this repetition of the macro,
278 starting again from the beginning in the next repetition. `C-d' means
279 to skip the remainder of this repetition and cancel further repetition.
280 `C-l' redraws the frame and asks you again for a character to specify
281 what to do. `C-r' enters a recursive editing level, in which you can
282 perform editing that is not part of the macro. When you exit the
283 recursive edit using `C-M-c', you are asked again how to continue with
284 the keyboard macro. If you type a <SPC> at this time, the rest of the
285 macro definition is executed. It is up to you to leave point and the
286 text in a state such that the rest of the macro will do what you want.
288 `C-u C-x q', which is `C-x q' with a numeric argument, performs a
289 different function. It enters a recursive edit reading input from the
290 keyboard, both when you type it during the definition of the macro and
291 when it is executed from the macro. During definition, the editing you
292 do inside the recursive edit does not become part of the macro. During
293 macro execution, the recursive edit gives you a chance to do some
294 particularized editing. *Note Recursive Edit::.
297 File: xemacs.info, Node: Key Bindings, Next: Syntax, Prev: Keyboard Macros, Up: Customization
299 Customizing Key Bindings
300 ========================
302 This section deals with the "keymaps" that define the bindings
303 between keys and functions, and shows how you can customize these
306 A command is a Lisp function whose definition provides for
307 interactive use. Like every Lisp function, a command has a function
308 name, which is a Lisp symbol whose name usually consists of lower case
313 * Keymaps:: Definition of the keymap data structure.
314 Names of Emacs's standard keymaps.
315 * Rebinding:: How to redefine one key's meaning conveniently.
316 * Disabling:: Disabling a command means confirmation is required
317 before it can be executed. This is done to protect
318 beginners from surprises.
321 File: xemacs.info, Node: Keymaps, Next: Rebinding, Up: Key Bindings
326 The bindings between characters and command functions are recorded in
327 data structures called "keymaps". Emacs has many of these. One, the
328 "global" keymap, defines the meanings of the single-character keys that
329 are defined regardless of major mode. It is the value of the variable
332 Each major mode has another keymap, its "local keymap", which
333 contains overriding definitions for the single-character keys that are
334 redefined in that mode. Each buffer records which local keymap is
335 installed for it at any time, and the current buffer's local keymap is
336 the only one that directly affects command execution. The local keymaps
337 for Lisp mode, C mode, and many other major modes always exist even when
338 not in use. They are the values of the variables `lisp-mode-map',
339 `c-mode-map', and so on. For less frequently used major modes, the
340 local keymap is sometimes constructed only when the mode is used for the
341 first time in a session, to save space.
343 There are local keymaps for the minibuffer, too; they contain various
344 completion and exit commands.
346 * `minibuffer-local-map' is used for ordinary input (no completion).
348 * `minibuffer-local-ns-map' is similar, except that <SPC> exits just
349 like <RET>. This is used mainly for Mocklisp compatibility.
351 * `minibuffer-local-completion-map' is for permissive completion.
353 * `minibuffer-local-must-match-map' is for strict completion and for
356 * `repeat-complex-command-map' is for use in `C-x <ESC>'.
358 * `isearch-mode-map' contains the bindings of the special keys which
359 are bound in the pseudo-mode entered with `C-s' and `C-r'.
361 Finally, each prefix key has a keymap which defines the key sequences
362 that start with it. For example, `ctl-x-map' is the keymap used for
363 characters following a `C-x'.
365 * `ctl-x-map' is the variable name for the map used for characters
368 * `help-map' is used for characters that follow `C-h'.
370 * `esc-map' is for characters that follow <ESC>. All Meta characters
371 are actually defined by this map.
373 * `ctl-x-4-map' is for characters that follow `C-x 4'.
375 * `mode-specific-map' is for characters that follow `C-c'.
377 The definition of a prefix key is the keymap to use for looking up
378 the following character. Sometimes the definition is actually a Lisp
379 symbol whose function definition is the following character keymap. The
380 effect is the same, but it provides a command name for the prefix key
381 that you can use as a description of what the prefix key is for. Thus
382 the binding of `C-x' is the symbol `Ctl-X-Prefix', whose function
383 definition is the keymap for `C-x' commands, the value of `ctl-x-map'.
385 Prefix key definitions can appear in either the global map or a
386 local map. The definitions of `C-c', `C-x', `C-h', and <ESC> as prefix
387 keys appear in the global map, so these prefix keys are always
388 available. Major modes can locally redefine a key as a prefix by
389 putting a prefix key definition for it in the local map.
391 A mode can also put a prefix definition of a global prefix character
392 such as `C-x' into its local map. This is how major modes override the
393 definitions of certain keys that start with `C-x'. This case is
394 special, because the local definition does not entirely replace the
395 global one. When both the global and local definitions of a key are
396 other keymaps, the next character is looked up in both keymaps, with
397 the local definition overriding the global one. The character after the
398 `C-x' is looked up in both the major mode's own keymap for redefined
399 `C-x' commands and in `ctl-x-map'. If the major mode's own keymap for
400 `C-x' commands contains `nil', the definition from the global keymap
401 for `C-x' commands is used.
404 File: xemacs.info, Node: Rebinding, Next: Disabling, Prev: Keymaps, Up: Key Bindings
406 Changing Key Bindings
407 ---------------------
409 You can redefine an Emacs key by changing its entry in a keymap.
410 You can change the global keymap, in which case the change is effective
411 in all major modes except those that have their own overriding local
412 definitions for the same key. Or you can change the current buffer's
413 local map, which affects all buffers using the same major mode.
417 * Interactive Rebinding:: Changing Key Bindings Interactively
418 * Programmatic Rebinding:: Changing Key Bindings Programmatically
419 * Key Bindings Using Strings:: Using Strings for Changing Key Bindings
422 File: xemacs.info, Node: Interactive Rebinding, Next: Programmatic Rebinding, Up: Rebinding
424 Changing Key Bindings Interactively
425 ...................................
427 `M-x global-set-key <RET> KEY CMD <RET>'
428 Defines KEY globally to run CMD.
430 `M-x local-set-key <RET> KEYS CMD <RET>'
431 Defines KEY locally (in the major mode now in effect) to run CMD.
433 `M-x local-unset-key <RET> KEYS <RET>'
434 Removes the local binding of KEY.
436 CMD is a symbol naming an interactively-callable function.
438 When called interactively, KEY is the next complete key sequence
439 that you type. When called as a function, KEY is a string, a vector of
440 events, or a vector of key-description lists as described in the
441 `define-key' function description. The binding goes in the current
442 buffer's local map, which is shared with other buffers in the same
445 The following example:
447 M-x global-set-key <RET> C-f next-line <RET>
449 redefines `C-f' to move down a line. The fact that CMD is read second
450 makes it serve as a kind of confirmation for KEY.
452 These functions offer no way to specify a particular prefix keymap as
453 the one to redefine in, but that is not necessary, as you can include
454 prefixes in KEY. KEY is read by reading characters one by one until
455 they amount to a complete key (that is, not a prefix key). Thus, if
456 you type `C-f' for KEY, Emacs enters the minibuffer immediately to read
457 CMD. But if you type `C-x', another character is read; if that
458 character is `4', another character is read, and so on. For example,
460 M-x global-set-key <RET> C-x 4 $ spell-other-window <RET>
462 redefines `C-x 4 $' to run the (fictitious) command
463 `spell-other-window'.
465 The most general way to modify a keymap is the function
466 `define-key', used in Lisp code (such as your init file). `define-key'
467 takes three arguments: the keymap, the key to modify in it, and the new
468 definition. *Note Init File::, for an example.
469 `substitute-key-definition' is used similarly; it takes three
470 arguments, an old definition, a new definition, and a keymap, and
471 redefines in that keymap all keys that were previously defined with the
472 old definition to have the new definition instead.
475 File: xemacs.info, Node: Programmatic Rebinding, Next: Key Bindings Using Strings, Prev: Interactive Rebinding, Up: Rebinding
477 Changing Key Bindings Programmatically
478 ......................................
480 You can use the functions `global-set-key' and `define-key' to
481 rebind keys under program control.
483 ``(global-set-key KEYS CMD)''
484 Defines KEYS globally to run CMD.
486 ``(define-key KEYMAP KEYS DEF)''
487 Defines KEYS to run DEF in the keymap KEYMAP.
489 KEYMAP is a keymap object.
491 KEYS is the sequence of keystrokes to bind.
493 DEF is anything that can be a key's definition:
495 * `nil', meaning key is undefined in this keymap
497 * A command, that is, a Lisp function suitable for interactive
500 * A string or key sequence vector, which is treated as a keyboard
503 * A keymap to define a prefix key
505 * A symbol so that when the key is looked up, the symbol stands for
506 its function definition, which should at that time be one of the
507 above, or another symbol whose function definition is used, and so
510 * A cons, `(string . defn)', meaning that DEFN is the definition
511 (DEFN should be a valid definition in its own right)
513 * A cons, `(keymap . char)', meaning use the definition of CHAR in
516 For backward compatibility, XEmacs allows you to specify key
517 sequences as strings. However, the preferred method is to use the
518 representations of key sequences as vectors of keystrokes. *Note
519 Keystrokes::, for more information about the rules for constructing key
522 Emacs allows you to abbreviate representations for key sequences in
523 most places where there is no ambiguity. Here are some rules for
526 * The keysym by itself is equivalent to a list of just that keysym,
527 i.e., `f1' is equivalent to `(f1)'.
529 * A keystroke by itself is equivalent to a vector containing just
530 that keystroke, i.e., `(control a)' is equivalent to `[(control
533 * You can use ASCII codes for keysyms that have them. i.e., `65' is
534 equivalent to `A'. (This is not so much an abbreviation as an
535 alternate representation.)
537 Here are some examples of programmatically binding keys:
540 ;;; Bind `my-command' to <f1>
541 (global-set-key 'f1 'my-command)
543 ;;; Bind `my-command' to Shift-f1
544 (global-set-key '(shift f1) 'my-command)
546 ;;; Bind `my-command' to C-c Shift-f1
547 (global-set-key '[(control c) (shift f1)] 'my-command)
549 ;;; Bind `my-command' to the middle mouse button.
550 (global-set-key 'button2 'my-command)
552 ;;; Bind `my-command' to <META> <CTL> <Right Mouse Button>
553 ;;; in the keymap that is in force when you are running `dired'.
554 (define-key dired-mode-map '(meta control button3) 'my-command)
557 File: xemacs.info, Node: Key Bindings Using Strings, Prev: Programmatic Rebinding, Up: Rebinding
559 Using Strings for Changing Key Bindings
560 .......................................
562 For backward compatibility, you can still use strings to represent
563 key sequences. Thus you can use commands like the following:
565 ;;; Bind `end-of-line' to C-f
566 (global-set-key "\C-f" 'end-of-line)
568 Note, however, that in some cases you may be binding more than one
569 key sequence by using a single command. This situation can arise
570 because in ASCII, `C-i' and <TAB> have the same representation.
571 Therefore, when Emacs sees:
573 (global-set-key "\C-i" 'end-of-line)
575 it is unclear whether the user intended to bind `C-i' or <TAB>. The
576 solution XEmacs adopts is to bind both of these key sequences.
578 After binding a command to two key sequences with a form like:
580 (define-key global-map "\^X\^I" 'command-1)
582 it is possible to redefine only one of those sequences like so:
584 (define-key global-map [(control x) (control i)] 'command-2)
585 (define-key global-map [(control x) tab] 'command-3)
587 This applies only when running under a window system. If you are
588 talking to Emacs through an ASCII-only channel, you do not get any of
591 Here is a table of pairs of key sequences that behave in a similar
600 control @ control space
603 File: xemacs.info, Node: Disabling, Prev: Rebinding, Up: Key Bindings
608 Disabling a command marks it as requiring confirmation before it can
609 be executed. The purpose of disabling a command is to prevent
610 beginning users from executing it by accident and being confused.
612 The direct mechanism for disabling a command is to have a non-`nil'
613 `disabled' property on the Lisp symbol for the command. These
614 properties are normally set by the user's init file with Lisp
617 (put 'delete-region 'disabled t)
621 If the value of the `disabled' property is a string, that string is
622 included in the message printed when the command is used:
624 (put 'delete-region 'disabled
625 "Text deleted this way cannot be yanked back!\n")
627 You can disable a command either by editing the init file directly
628 or with the command `M-x disable-command', which edits the init file
629 for you. *Note Init File::.
631 When you attempt to invoke a disabled command interactively in Emacs,
632 a window is displayed containing the command's name, its documentation,
633 and some instructions on what to do next; then Emacs asks for input
634 saying whether to execute the command as requested, enable it and
635 execute, or cancel it. If you decide to enable the command, you are
636 asked whether to do this permanently or just for the current session.
637 Enabling permanently works by automatically editing your init file.
638 You can use `M-x enable-command' at any time to enable any command
641 Whether a command is disabled is independent of what key is used to
642 invoke it; it also applies if the command is invoked using `M-x'.
643 Disabling a command has no effect on calling it as a function from Lisp
647 File: xemacs.info, Node: Syntax, Next: Init File, Prev: Key Bindings, Up: Customization
652 All the Emacs commands which parse words or balance parentheses are
653 controlled by the "syntax table". The syntax table specifies which
654 characters are opening delimiters, which are parts of words, which are
655 string quotes, and so on. Actually, each major mode has its own syntax
656 table (though sometimes related major modes use the same one) which it
657 installs in each buffer that uses that major mode. The syntax table
658 installed in the current buffer is the one that all commands use, so we
659 call it "the" syntax table. A syntax table is a Lisp object, a vector
660 of length 256 whose elements are numbers.
664 * Entry: Syntax Entry. What the syntax table records for each character.
665 * Change: Syntax Change. How to change the information.
668 File: xemacs.info, Node: Syntax Entry, Next: Syntax Change, Up: Syntax
670 Information About Each Character
671 --------------------------------
673 The syntax table entry for a character is a number that encodes six
674 pieces of information:
676 * The syntactic class of the character, represented as a small
679 * The matching delimiter, for delimiter characters only (the
680 matching delimiter of `(' is `)', and vice versa)
682 * A flag saying whether the character is the first character of a
683 two-character comment starting sequence
685 * A flag saying whether the character is the second character of a
686 two-character comment starting sequence
688 * A flag saying whether the character is the first character of a
689 two-character comment ending sequence
691 * A flag saying whether the character is the second character of a
692 two-character comment ending sequence
694 The syntactic classes are stored internally as small integers, but
695 are usually described to or by the user with characters. For example,
696 `(' is used to specify the syntactic class of opening delimiters. Here
697 is a table of syntactic classes, with the characters that specify them.
700 The class of whitespace characters.
703 The class of word-constituent characters.
706 The class of characters that are part of symbol names but not
707 words. This class is represented by `_' because the character `_'
708 has this class in both C and Lisp.
711 The class of punctuation characters that do not fit into any other
715 The class of opening delimiters.
718 The class of closing delimiters.
721 The class of expression-adhering characters. These characters are
722 part of a symbol if found within or adjacent to one, and are part
723 of a following expression if immediately preceding one, but are
724 like whitespace if surrounded by whitespace.
727 The class of string-quote characters. They match each other in
728 pairs, and the characters within the pair all lose their syntactic
729 significance except for the `\' and `/' classes of escape
730 characters, which can be used to include a string-quote inside the
734 The class of self-matching delimiters. This is intended for TeX's
735 `$', which is used both to enter and leave math mode. Thus, a
736 pair of matching `$' characters surround each piece of math mode
737 TeX input. A pair of adjacent `$' characters act like a single
738 one for purposes of matching.
741 The class of escape characters that always just deny the following
742 character its special syntactic significance. The character after
743 one of these escapes is always treated as alphabetic.
746 The class of C-style escape characters. In practice, these are
747 treated just like `/'-class characters, because the extra
748 possibilities for C escapes (such as being followed by digits)
749 have no effect on where the containing expression ends.
752 The class of comment-starting characters. Only single-character
753 comment starters (such as `;' in Lisp mode) are represented this
757 The class of comment-ending characters. Newline has this syntax in
760 The characters flagged as part of two-character comment delimiters
761 can have other syntactic functions most of the time. For example, `/'
762 and `*' in C code, when found separately, have nothing to do with
763 comments. The comment-delimiter significance overrides when the pair of
764 characters occur together in the proper order. Only the list and sexp
765 commands use the syntax table to find comments; the commands
766 specifically for comments have other variables that tell them where to
767 find comments. Moreover, the list and sexp commands notice comments
768 only if `parse-sexp-ignore-comments' is non-`nil'. This variable is set
769 to `nil' in modes where comment-terminator sequences are liable to
770 appear where there is no comment, for example, in Lisp mode where the
771 comment terminator is a newline but not every newline ends a comment.
774 File: xemacs.info, Node: Syntax Change, Prev: Syntax Entry, Up: Syntax
776 Altering Syntax Information
777 ---------------------------
779 It is possible to alter a character's syntax table entry by storing
780 a new number in the appropriate element of the syntax table, but it
781 would be hard to determine what number to use. Emacs therefore
782 provides a command that allows you to specify the syntactic properties
783 of a character in a convenient way.
785 `M-x modify-syntax-entry' is the command to change a character's
786 syntax. It can be used interactively and is also used by major modes
787 to initialize their own syntax tables. Its first argument is the
788 character to change. The second argument is a string that specifies the
789 new syntax. When called from Lisp code, there is a third, optional
790 argument, which specifies the syntax table in which to make the change.
791 If not supplied, or if this command is called interactively, the third
792 argument defaults to the current buffer's syntax table.
794 1. The first character in the string specifies the syntactic class.
795 It is one of the characters in the previous table (*note Syntax
798 2. The second character is the matching delimiter. For a character
799 that is not an opening or closing delimiter, this should be a
800 space, and may be omitted if no following characters are needed.
802 3. The remaining characters are flags. The flag characters allowed
806 Flag this character as the first of a two-character comment
810 Flag this character as the second of a two-character comment
814 Flag this character as the first of a two-character comment
818 Flag this character as the second of a two-character comment
821 Use `C-h s' (`describe-syntax') to display a description of the
822 contents of the current syntax table. The description of each
823 character includes both the string you have to pass to
824 `modify-syntax-entry' to set up that character's current syntax, and
825 some English to explain that string if necessary.
828 File: xemacs.info, Node: Init File, Next: Audible Bell, Prev: Syntax, Up: Customization
833 When you start Emacs, it normally loads either `.xemacs/init.el' or
834 the file `.emacs' (whichever comes first) in your home directory. This
835 file, if it exists, should contain Lisp code. It is called your
836 initialization file or "init file". Use the command line switch `-q'
837 to tell Emacs whether to load an init file (*note Entering Emacs::).
838 Use the command line switch `-user-init-file' (*note Command
839 Switches::) to tell Emacs to load a different file instead of
840 `~/.xemacs/init.el'/`~/.emacs'.
842 When the init file is read, the variable `user-init-file' says which
843 init file was loaded.
845 At some sites there is a "default init file", which is the library
846 named `default.el', found via the standard search path for libraries.
847 The Emacs distribution contains no such library; your site may create
848 one for local customizations. If this library exists, it is loaded
849 whenever you start Emacs. But your init file, if any, is loaded first;
850 if it sets `inhibit-default-init' non-`nil', then `default' is not
853 If you have a large amount of code in your init file, you should
854 byte-compile it to `~/.xemacs/init.elc' or `~/.emacs.elc'.
858 * Init Syntax:: Syntax of constants in Emacs Lisp.
859 * Init Examples:: How to do some things with an init file.
860 * Terminal Init:: Each terminal type can have an init file.
863 File: xemacs.info, Node: Init Syntax, Next: Init Examples, Up: Init File
868 The init file contains one or more Lisp function call expressions.
869 Each consists of a function name followed by arguments, all surrounded
870 by parentheses. For example, `(setq fill-column 60)' represents a call
871 to the function `setq' which is used to set the variable `fill-column'
872 (*note Filling::) to 60.
874 The second argument to `setq' is an expression for the new value of
875 the variable. This can be a constant, a variable, or a function call
876 expression. In the init file, constants are used most of the time.
880 Integers are written in decimal, with an optional initial minus
883 If a sequence of digits is followed by a period and another
884 sequence of digits, it is interpreted as a floating point number.
886 The number prefixes `#b', `#o', and `#x' are supported to
887 represent numbers in binary, octal, and hexadecimal notation (or
891 Lisp string syntax is the same as C string syntax with a few extra
892 features. Use a double-quote character to begin and end a string
895 Newlines and special characters may be present literally in
896 strings. They can also be represented as backslash sequences:
897 `\n' for newline, `\b' for backspace, `\r' for return, `\t' for
898 tab, `\f' for formfeed (control-l), `\e' for escape, `\\' for a
899 backslash, `\"' for a double-quote, or `\OOO' for the character
900 whose octal code is OOO. Backslash and double-quote are the only
901 characters for which backslash sequences are mandatory.
903 You can use `\C-' as a prefix for a control character, as in
904 `\C-s' for ASCII Control-S, and `\M-' as a prefix for a Meta
905 character, as in `\M-a' for Meta-A or `\M-\C-a' for Control-Meta-A.
908 Lisp character constant syntax consists of a `?' followed by
909 either a character or an escape sequence starting with `\'.
910 Examples: `?x', `?\n', `?\"', `?\)'. Note that strings and
911 characters are not interchangeable in Lisp; some contexts require
912 one and some contexts require the other.
915 `t' stands for `true'.
918 `nil' stands for `false'.
921 Write a single-quote (') followed by the Lisp object you want.
924 File: xemacs.info, Node: Init Examples, Next: Terminal Init, Prev: Init Syntax, Up: Init File
929 Here are some examples of doing certain commonly desired things with
932 * Make <TAB> in C mode just insert a tab if point is in the middle
935 (setq c-tab-always-indent nil)
937 Here we have a variable whose value is normally `t' for `true' and
938 the alternative is `nil' for `false'.
940 * Make searches case sensitive by default (in all buffers that do not
943 (setq-default case-fold-search nil)
945 This sets the default value, which is effective in all buffers
946 that do not have local values for the variable. Setting
947 `case-fold-search' with `setq' affects only the current buffer's
948 local value, which is probably not what you want to do in an init
951 * Make Text mode the default mode for new buffers.
953 (setq default-major-mode 'text-mode)
955 Note that `text-mode' is used because it is the command for
956 entering the mode we want. A single-quote is written before it to
957 make a symbol constant; otherwise, `text-mode' would be treated as
960 * Turn on Auto Fill mode automatically in Text mode and related
964 '(lambda () (auto-fill-mode 1)))
966 Here we have a variable whose value should be a Lisp function. The
967 function we supply is a list starting with `lambda', and a single
968 quote is written in front of it to make it (for the purpose of this
969 `setq') a list constant rather than an expression. Lisp functions
970 are not explained here; for mode hooks it is enough to know that
971 `(auto-fill-mode 1)' is an expression that will be executed when
972 Text mode is entered. You could replace it with any other
973 expression that you like, or with several expressions in a row.
975 (setq text-mode-hook 'turn-on-auto-fill)
977 This is another way to accomplish the same result.
978 `turn-on-auto-fill' is a symbol whose function definition is
979 `(lambda () (auto-fill-mode 1))'.
981 * Load the installed Lisp library named `foo' (actually a file
982 `foo.elc' or `foo.el' in a standard Emacs directory).
986 When the argument to `load' is a relative pathname, not starting
987 with `/' or `~', `load' searches the directories in `load-path'
990 * Load the compiled Lisp file `foo.elc' from your home directory.
994 Here an absolute file name is used, so no searching is done.
996 * Rebind the key `C-x l' to run the function `make-symbolic-link'.
998 (global-set-key "\C-xl" 'make-symbolic-link)
1002 (define-key global-map "\C-xl" 'make-symbolic-link)
1004 Note once again the single-quote used to refer to the symbol
1005 `make-symbolic-link' instead of its value as a variable.
1007 * Do the same thing for C mode only.
1009 (define-key c-mode-map "\C-xl" 'make-symbolic-link)
1011 * Bind the function key <F1> to a command in C mode. Note that the
1012 names of function keys must be lower case.
1014 (define-key c-mode-map 'f1 'make-symbolic-link)
1016 * Bind the shifted version of <F1> to a command.
1018 (define-key c-mode-map '(shift f1) 'make-symbolic-link)
1020 * Redefine all keys which now run `next-line' in Fundamental mode to
1021 run `forward-line' instead.
1023 (substitute-key-definition 'next-line 'forward-line
1026 * Make `C-x C-v' undefined.
1028 (global-unset-key "\C-x\C-v")
1030 One reason to undefine a key is so that you can make it a prefix.
1031 Simply defining `C-x C-v ANYTHING' would make `C-x C-v' a prefix,
1032 but `C-x C-v' must be freed of any non-prefix definition first.
1034 * Make `$' have the syntax of punctuation in Text mode. Note the
1035 use of a character constant for `$'.
1037 (modify-syntax-entry ?\$ "." text-mode-syntax-table)
1039 * Enable the use of the command `eval-expression' without
1042 (put 'eval-expression 'disabled nil)
1045 File: xemacs.info, Node: Terminal Init, Prev: Init Examples, Up: Init File
1047 Terminal-Specific Initialization
1048 --------------------------------
1050 Each terminal type can have a Lisp library to be loaded into Emacs
1051 when it is run on that type of terminal. For a terminal type named
1052 TERMTYPE, the library is called `term/TERMTYPE' and it is found by
1053 searching the directories `load-path' as usual and trying the suffixes
1054 `.elc' and `.el'. Normally it appears in the subdirectory `term' of
1055 the directory where most Emacs libraries are kept.
1057 The usual purpose of the terminal-specific library is to define the
1058 escape sequences used by the terminal's function keys using the library
1059 `keypad.el'. See the file `term/vt100.el' for an example of how this
1062 When the terminal type contains a hyphen, only the part of the name
1063 before the first hyphen is significant in choosing the library name.
1064 Thus, terminal types `aaa-48' and `aaa-30-rv' both use the library
1065 `term/aaa'. The code in the library can use `(getenv "TERM")' to find
1066 the full terminal type name.
1068 The library's name is constructed by concatenating the value of the
1069 variable `term-file-prefix' and the terminal type. Your init file can
1070 prevent the loading of the terminal-specific library by setting
1071 `term-file-prefix' to `nil'. *Note Init File::.
1073 The value of the variable `term-setup-hook', if not `nil', is called
1074 as a function of no arguments at the end of Emacs initialization, after
1075 both your init file and any terminal-specific library have been read.
1076 *Note Init File::. You can set the value in the init file to override
1077 part of any of the terminal-specific libraries and to define
1078 initializations for terminals that do not have a library.
1081 File: xemacs.info, Node: Audible Bell, Next: Faces, Prev: Init File, Up: Customization
1083 Changing the Bell Sound
1084 =======================
1086 You can now change how the audible bell sounds using the variable
1089 `sound-alist''s value is an list associating symbols with, among
1090 other things, strings of audio-data. When `ding' is called with one of
1091 the symbols, the associated sound data is played instead of the
1092 standard beep. This only works if you are logged in on the console of a
1093 machine with audio hardware. To listen to a sound of the provided type,
1094 call the function `play-sound' with the argument SOUND. You can also
1095 set the volume of the sound with the optional argument VOLUME.
1097 Each element of `sound-alist' is a list describing a sound. The
1098 first element of the list is the name of the sound being defined.
1099 Subsequent elements of the list are alternating keyword/value pairs:
1102 A string of raw sound data, or the name of another sound to play.
1103 The symbol `t' here means use the default X beep.
1106 An integer from 0-100, defaulting to `bell-volume'.
1109 If using the default X beep, the pitch (Hz) to generate.
1112 If using the default X beep, the duration (milliseconds).
1114 For compatibility, elements of `sound-alist' may also be of the form:
1116 ( SOUND-NAME . <SOUND> )
1117 ( SOUND-NAME <VOLUME> <SOUND> )
1119 You should probably add things to this list by calling the function
1122 Note that you can only play audio data if running on the console
1123 screen of a machine with audio hardware which emacs understands, which
1124 at this time means a Sun SparcStation, SGI, or HP9000s700.
1126 Also note that the pitch, duration, and volume options are available
1127 everywhere, but most X servers ignore the `pitch' option.
1129 The variable `bell-volume' should be an integer from 0 to 100, with
1130 100 being loudest, which controls how loud the sounds emacs makes
1131 should be. Elements of the `sound-alist' may override this value.
1132 This variable applies to the standard X bell sound as well as sound
1135 If the symbol `t' is in place of a sound-string, Emacs uses the
1136 default X beep. This allows you to define beep-types of different
1137 volumes even when not running on the console.
1139 You can add things to this list by calling the function
1140 `load-sound-file', which reads in an audio-file and adds its data to
1141 the sound-alist. You can specify the sound with the SOUND-NAME argument
1142 and the file into which the sounds are loaded with the FILENAME
1143 argument. The optional VOLUME argument sets the volume.
1145 `load-sound-file (FILENAME SOUND-NAME &optional VOLUME)'
1147 To load and install some sound files as beep-types, use the function
1148 `load-default-sounds' (note that this only works if you are on display
1149 0 of a machine with audio hardware).
1151 The following beep-types are used by Emacs itself. Other Lisp
1152 packages may use other beep types, but these are the ones that the C
1153 kernel of Emacs uses.
1156 An auto-save does not succeed
1159 The Emacs command loop catches an error
1162 You type a key that is undefined
1165 You use an undefined mouse-click combination
1168 Completion was not possible
1171 You type something other than the required `y' or `n'
1174 You type something other than `yes' or `no'