This is Info file ../info/emacs, produced by Makeinfo-1.64 from the input file ../texi/emacs.texi. This is the thirteenth edition of the `GNU Emacs Manual', updated for Emacs version 20.3 Editors * Emacs: (emacs). The extensible self-documenting text editor. Published by the Free Software Foundation 59 Temple Place, Suite 330 Boston, MA 02111-1307 USA Copyright (C) 1985, 1986, 1987, 1993, 1994, 1995, 1996, 1997, 1998 Free Software Foundation, Inc. Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided also that the sections entitled "The GNU Manifesto", "Distribution" and "GNU General Public License" are included exactly as in the original, and provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Permission is granted to copy and distribute translations of this manual into another language, under the above conditions for modified versions, except that the sections entitled "The GNU Manifesto", "Distribution" and "GNU General Public License" may be included in a translation approved by the Free Software Foundation instead of in the original English. ifinfo  File: emacs, Node: File Variables, Prev: Locals, Up: Variables Local Variables in Files ------------------------ A file can specify local variable values for use when you edit the file with Emacs. Visiting the file checks for local variable specifications; it automatically makes these variables local to the buffer, and sets them to the values specified in the file. There are two ways to specify local variable values: in the first line, or with a local variables list. Here's how to specify them in the first line: -*- mode: MODENAME; VAR: VALUE; ... -*- You can specify any number of variables/value pairs in this way, each pair with a colon and semicolon as shown above. `mode: MODENAME;' specifies the major mode; this should come first in the line. The VALUEs are not evaluated; they are used literally. Here is an example that specifies Lisp mode and sets two variables with numeric values: ;; -*-mode: Lisp; fill-column: 75; comment-column: 50; -*- You can also specify the coding system for a file in this way: just specify a value for the "variable" named `coding'. The "value" must be a coding system name that Emacs recognizes. *Note Coding Systems::. A "local variables list" goes near the end of the file, in the last page. (It is often best to put it on a page by itself.) The local variables list starts with a line containing the string `Local Variables:', and ends with a line containing the string `End:'. In between come the variable names and values, one set per line, as `VARIABLE: VALUE'. The VALUEs are not evaluated; they are used literally. If a file has both a local variables list and a `-*-' line, Emacs processes *everything* in the `-*-' line first, and *everything* in the local variables list afterward. Here is an example of a local variables list: ;;; Local Variables: *** ;;; mode:lisp *** ;;; comment-column:0 *** ;;; comment-start: ";;; " *** ;;; comment-end:"***" *** ;;; End: *** As you see, each line starts with the prefix `;;; ' and each line ends with the suffix ` ***'. Emacs recognizes these as the prefix and suffix based on the first line of the list, by finding them surrounding the magic string `Local Variables:'; then it automatically discards them from the other lines of the list. The usual reason for using a prefix and/or suffix is to embed the local variables list in a comment, so it won't confuse other programs that the file is intended as input for. The example above is for a language where comment lines start with `;;; ' and end with `***'; the local values for `comment-start' and `comment-end' customize the rest of Emacs for this unusual syntax. Don't use a prefix (or a suffix) if you don't need one. Two "variable names" have special meanings in a local variables list: a value for the variable `mode' really sets the major mode, and a value for the variable `eval' is simply evaluated as an expression and the value is ignored. `mode' and `eval' are not real variables; setting variables named `mode' and `eval' in any other context has no special meaning. If `mode' is used to set a major mode, it should be the first "variable" in the list. You can use the `mode' "variable" to set minor modes as well as major modes; in fact, you can use it more than once, first to set the major mode and then to set minor modes which are specific to particular buffers. But most minor modes should not be specified in the file in any fashion, because they represent user preferences. For example, you may be tempted to try to turn on Auto Fill mode with a local variable list. That is a mistake. The choice of Auto Fill mode or not is a matter of individual taste, not a matter of the contents of particular files. If you want to use Auto Fill, set up major mode hooks with your `.emacs' file to turn it on (when appropriate) for you alone (*note Init File::.). Don't use a local variable list to impose your taste on everyone. It does not work to specify the "variable" `coding' in a local variables list; `coding' is implemented in a special way and it works only in the `-*-' construct. The start of the local variables list must be no more than 3000 characters from the end of the file, and must be in the last page if the file is divided into pages. Otherwise, Emacs will not notice it is there. The purpose of this rule is so that a stray `Local Variables:' not in the last page does not confuse Emacs, and so that visiting a long file that is all one page and has no local variables list need not take the time to search the whole file. Use the command `normal-mode' to reset the local variables and major mode of a buffer according to the file name and contents, including the local variables list if any. *Note Choosing Modes::. The variable `enable-local-variables' controls whether to process local variables in files, and thus gives you a chance to override them. Its default value is `t', which means do process local variables in files. If you set the value to `nil', Emacs simply ignores local variables in files. Any other value says to query you about each file that has local variables, showing you the local variable specifications so you can judge. The `eval' "variable," and certain actual variables, create a special risk; when you visit someone else's file, local variable specifications for these could affect your Emacs in arbitrary ways. Therefore, the option `enable-local-eval' controls whether Emacs processes `eval' variables, as well variables with names that end in `-hook', `-hooks', `-function' or `-functions', and certain other variables. The three possibilities for the option's value are `t', `nil', and anything else, just as for `enable-local-variables'. The default is `maybe', which is neither `t' nor `nil', so normally Emacs does ask for confirmation about file settings for these variables.  File: emacs, Node: Keyboard Macros, Next: Key Bindings, Prev: Variables, Up: Customization Keyboard Macros =============== A "keyboard macro" is a command defined by the user to stand for another sequence of keys. For example, if you discover that you are about to type `C-n C-d' forty times, you can speed your work by defining a keyboard macro to do `C-n C-d' and calling it with a repeat count of forty. `C-x (' Start defining a keyboard macro (`start-kbd-macro'). `C-x )' End the definition of a keyboard macro (`end-kbd-macro'). `C-x e' Execute the most recent keyboard macro (`call-last-kbd-macro'). `C-u C-x (' Re-execute last keyboard macro, then add more keys to its definition. `C-x q' When this point is reached during macro execution, ask for confirmation (`kbd-macro-query'). `M-x name-last-kbd-macro' Give a command name (for the duration of the session) to the most recently defined keyboard macro. `M-x insert-kbd-macro' Insert in the buffer a keyboard macro's definition, as Lisp code. `C-x C-k' Edit a previously defined keyboard macro (`edit-kbd-macro'). `M-x apply-macro-to-region-lines' Run the last keyboard macro on each complete line in the region. Keyboard macros differ from ordinary Emacs commands in that they are written in the Emacs command language rather than in Lisp. This makes it easier for the novice to write them, and makes them more convenient as temporary hacks. However, the Emacs command language is not powerful enough as a programming language to be useful for writing anything intelligent or general. For such things, Lisp must be used. You define a keyboard macro while executing the commands which are the definition. Put differently, as you define a keyboard macro, the definition is being executed for the first time. This way, you can see what the effects of your commands are, so that you don't have to figure them out in your head. When you are finished, the keyboard macro is defined and also has been, in effect, executed once. You can then do the whole thing over again by invoking the macro. * Menu: * Basic Kbd Macro:: Defining and running keyboard macros. * Save Kbd Macro:: Giving keyboard macros names; saving them in files. * Kbd Macro Query:: Making keyboard macros do different things each time.  File: emacs, Node: Basic Kbd Macro, Next: Save Kbd Macro, Up: Keyboard Macros Basic Use --------- To start defining a keyboard macro, type the `C-x (' command (`start-kbd-macro'). From then on, your keys continue to be executed, but also become part of the definition of the macro. `Def' appears in the mode line to remind you of what is going on. When you are finished, the `C-x )' command (`end-kbd-macro') terminates the definition (without becoming part of it!). For example, C-x ( M-f foo C-x ) defines a macro to move forward a word and then insert `foo'. The macro thus defined can be invoked again with the `C-x e' command (`call-last-kbd-macro'), which may be given a repeat count as a numeric argument to execute the macro many times. `C-x )' can also be given a repeat count as an argument, in which case it repeats the macro that many times right after defining it, but defining the macro counts as the first repetition (since it is executed as you define it). Therefore, giving `C-x )' an argument of 4 executes the macro immediately 3 additional times. An argument of zero to `C-x e' or `C-x )' means repeat the macro indefinitely (until it gets an error or you type `C-g' or, on MS-DOS, `C-BREAK'). If you wish to repeat an operation at regularly spaced places in the text, define a macro and include as part of the macro the commands to move to the next place you want to use it. For example, if you want to change each line, you should position point at the start of a line, and define a macro to change that line and leave point at the start of the next line. Then repeating the macro will operate on successive lines. After you have terminated the definition of a keyboard macro, you can add to the end of its definition by typing `C-u C-x ('. This is equivalent to plain `C-x (' followed by retyping the whole definition so far. As a consequence it re-executes the macro as previously defined. You can use function keys in a keyboard macro, just like keyboard keys. You can even use mouse events, but be careful about that: when the macro replays the mouse event, it uses the original mouse position of that event, the position that the mouse had while you were defining the macro. The effect of this may be hard to predict. (Using the current mouse position would be even less predictable.) One thing that doesn't always work well in a keyboard macro is the command `C-M-c' (`exit-recursive-edit'). When this command exits a recursive edit that started within the macro, it works as you'd expect. But if it exits a recursive edit that started before you invoked the keyboard macro, it also necessarily exits the keyboard macro as part of the process. You can edit a keyboard macro already defined by typing `C-x C-k' (`edit-kbd-macro'). Follow that with the keyboard input that you would use to invoke the macro--`C-x e' or `M-x NAME' or some other key sequence. This formats the macro definition in a buffer and enters a specialized major mode for editing it. Type `C-h m' once in that buffer to display details of how to edit the macro. When you are finished editing, type `C-c C-c'. The command `M-x apply-macro-to-region-lines' repeats the last defined keyboard macro on each complete line within the current region. It does this line by line, by moving point to the beginning of the line and then executing the macro.  File: emacs, Node: Save Kbd Macro, Next: Kbd Macro Query, Prev: Basic Kbd Macro, Up: Keyboard Macros Naming and Saving Keyboard Macros --------------------------------- If you wish to save a keyboard macro for longer than until you define the next one, you must give it a name using `M-x name-last-kbd-macro'. This reads a name as an argument using the minibuffer and defines that name to execute the macro. The macro name is a Lisp symbol, and defining it in this way makes it a valid command name for calling with `M-x' or for binding a key to with `global-set-key' (*note Keymaps::.). If you specify a name that has a prior definition other than another keyboard macro, an error message is printed and nothing is changed. Once a macro has a command name, you can save its definition in a file. Then it can be used in another editing session. First, visit the file you want to save the definition in. Then use this command: M-x insert-kbd-macro RET MACRONAME RET This inserts some Lisp code that, when executed later, will define the same macro with the same definition it has now. (You need not understand Lisp code to do this, because `insert-kbd-macro' writes the Lisp code for you.) Then save the file. You can load the file later with `load-file' (*note Lisp Libraries::.). If the file you save in is your init file `~/.emacs' (*note Init File::.) then the macro will be defined each time you run Emacs. If you give `insert-kbd-macro' a numeric argument, it makes additional Lisp code to record the keys (if any) that you have bound to the keyboard macro, so that the macro will be reassigned the same keys when you load the file.  File: emacs, Node: Kbd Macro Query, Prev: Save Kbd Macro, Up: Keyboard Macros Executing Macros with Variations -------------------------------- Using `C-x q' (`kbd-macro-query'), you can get an effect similar to that of `query-replace', where the macro asks you each time around whether to make a change. While defining the macro, type `C-x q' at the point where you want the query to occur. During macro definition, the `C-x q' does nothing, but when you run the macro later, `C-x q' asks you interactively whether to continue. The valid responses when `C-x q' asks are SPC (or `y'), DEL (or `n'), RET (or `q'), `C-l' and `C-r'. The answers are the same as in `query-replace', though not all of the `query-replace' options are meaningful. These responses include SPC to continue, and DEL to skip the remainder of this repetition of the macro and start right away with the next repetition. RET means to skip the remainder of this repetition and cancel further repetitions. `C-l' redraws the screen and asks you again for a character to say what to do. `C-r' enters a recursive editing level, in which you can perform editing which is not part of the macro. When you exit the recursive edit using `C-M-c', you are asked again how to continue with the keyboard macro. If you type a SPC at this time, the rest of the macro definition is executed. It is up to you to leave point and the text in a state such that the rest of the macro will do what you want. `C-u C-x q', which is `C-x q' with a numeric argument, performs a completely different function. It enters a recursive edit reading input from the keyboard, both when you type it during the definition of the macro, and when it is executed from the macro. During definition, the editing you do inside the recursive edit does not become part of the macro. During macro execution, the recursive edit gives you a chance to do some particularized editing on each repetition. *Note Recursive Edit::.  File: emacs, Node: Key Bindings, Next: Keyboard Translations, Prev: Keyboard Macros, Up: Customization Customizing Key Bindings ======================== This section describes "key bindings", which map keys to commands, and "keymaps", which record key bindings. It also explains how to customize key bindings. Recall that a command is a Lisp function whose definition provides for interactive use. Like every Lisp function, a command has a function name which usually consists of lower-case letters and hyphens. * Menu: * Keymaps:: Generalities. The global keymap. * Prefix Keymaps:: Keymaps for prefix keys. * Local Keymaps:: Major and minor modes have their own keymaps. * Minibuffer Maps:: The minibuffer uses its own local keymaps. * Rebinding:: How to redefine one key's meaning conveniently. * Init Rebinding:: Rebinding keys with your init file, `.emacs'. * Function Keys:: Rebinding terminal function keys. * Named ASCII Chars:: Distinguishing TAB from `C-i', and so on. * Mouse Buttons:: Rebinding mouse buttons in Emacs. * Disabling:: Disabling a command means confirmation is required before it can be executed. This is done to protect beginners from surprises.  File: emacs, Node: Keymaps, Next: Prefix Keymaps, Up: Key Bindings Keymaps ------- The bindings between key sequences and command functions are recorded in data structures called "keymaps". Emacs has many of these, each used on particular occasions. Recall that a "key sequence" ("key", for short) is a sequence of "input events" that have a meaning as a unit. Input events include characters, function keys and mouse buttons--all the inputs that you can send to the computer with your terminal. A key sequence gets its meaning from its "binding", which says what command it runs. The function of keymaps is to record these bindings. The "global" keymap is the most important keymap because it is always in effect. The global keymap defines keys for Fundamental mode; most of these definitions are common to most or all major modes. Each major or minor mode can have its own keymap which overrides the global definitions of some keys. For example, a self-inserting character such as `g' is self-inserting because the global keymap binds it to the command `self-insert-command'. The standard Emacs editing characters such as `C-a' also get their standard meanings from the global keymap. Commands to rebind keys, such as `M-x global-set-key', actually work by storing the new binding in the proper place in the global map. *Note Rebinding::. Meta characters work differently; Emacs translates each Meta character into a pair of characters starting with ESC. When you type the character `M-a' in a key sequence, Emacs replaces it with `ESC a'. A meta key comes in as a single input event, but becomes two events for purposes of key bindings. The reason for this is historical, and we might change it someday. Most modern keyboards have function keys as well as character keys. Function keys send input events just as character keys do, and keymaps can have bindings for them. On many terminals, typing a function key actually sends the computer a sequence of characters; the precise details of the sequence depends on which function key and on the model of terminal you are using. (Often the sequence starts with `ESC ['.) If Emacs understands your terminal type properly, it recognizes the character sequences forming function keys wherever they occur in a key sequence (not just at the beginning). Thus, for most purposes, you can pretend the function keys reach Emacs directly and ignore their encoding as character sequences. Mouse buttons also produce input events. These events come with other data--the window and position where you pressed or released the button, and a time stamp. But only the choice of button matters for key bindings; the other data matters only if a command looks at it. (Commands designed for mouse invocation usually do look at the other data.) A keymap records definitions for single events. Interpreting a key sequence of multiple events involves a chain of keymaps. The first keymap gives a definition for the first event; this definition is another keymap, which is used to look up the second event in the sequence, and so on. Key sequences can mix function keys and characters. For example, `C-x SELECT' is meaningful. If you make SELECT a prefix key, then `SELECT C-n' makes sense. You can even mix mouse events with keyboard events, but we recommend against it, because such sequences are inconvenient to type in. As a user, you can redefine any key; but it might be best to stick to key sequences that consist of `C-c' followed by a letter. These keys are "reserved for users," so they won't conflict with any properly designed Emacs extension. If you redefine some other key, your definition may be overridden by certain extensions or major modes which redefine the same key.  File: emacs, Node: Prefix Keymaps, Next: Local Keymaps, Prev: Keymaps, Up: Key Bindings Prefix Keymaps -------------- A prefix key such as `C-x' or ESC has its own keymap, which holds the definition for the event that immediately follows that prefix. The definition of a prefix key is usually the keymap to use for looking up the following event. The definition can also be a Lisp symbol whose function definition is the following keymap; the effect is the same, but it provides a command name for the prefix key that can be used as a description of what the prefix key is for. Thus, the binding of `C-x' is the symbol `Ctl-X-Prefix', whose function definition is the keymap for `C-x' commands. The definitions of `C-c', `C-x', `C-h' and ESC as prefix keys appear in the global map, so these prefix keys are always available. Aside from ordinary prefix keys, there is a fictitious "prefix key" which represents the menu bar; see *Note Menu Bar: (elisp)Menu Bar, for special information about menu bar key bindings. Mouse button events that invoke pop-up menus are also prefix keys; see *Note Menu Keymaps: (elisp)Menu Keymaps, for more details. Some prefix keymaps are stored in variables with names: * `ctl-x-map' is the variable name for the map used for characters that follow `C-x'. * `help-map' is for characters that follow `C-h'. * `esc-map' is for characters that follow ESC. Thus, all Meta characters are actually defined by this map. * `ctl-x-4-map' is for characters that follow `C-x 4'. * `mode-specific-map' is for characters that follow `C-c'.  File: emacs, Node: Local Keymaps, Next: Minibuffer Maps, Prev: Prefix Keymaps, Up: Key Bindings Local Keymaps ------------- So far we have explained the ins and outs of the global map. Major modes customize Emacs by providing their own key bindings in "local keymaps". For example, C mode overrides TAB to make it indent the current line for C code. Portions of text in the buffer can specify their own keymaps to substitute for the keymap of the buffer's major mode. Minor modes can also have local keymaps. Whenever a minor mode is in effect, the definitions in its keymap override both the major mode's local keymap and the global keymap. The local keymaps for Lisp mode and several other major modes always exist even when not in use. These are kept in variables named `lisp-mode-map' and so on. For major modes less often used, the local keymap is normally constructed only when the mode is used for the first time in a session. This is to save space. If you wish to change one of these keymaps, you must use the major mode's "mode hook"--see below. All minor mode keymaps are created in advance. There is no way to defer their creation until the first time the minor mode is enabled. A local keymap can locally redefine a key as a prefix key by defining it as a prefix keymap. If the key is also defined globally as a prefix, then its local and global definitions (both keymaps) effectively combine: both of them are used to look up the event that follows the prefix key. Thus, if the mode's local keymap defines `C-c' as another keymap, and that keymap defines `C-z' as a command, this provides a local meaning for `C-c C-z'. This does not affect other sequences that start with `C-c'; if those sequences don't have their own local bindings, their global bindings remain in effect. Another way to think of this is that Emacs handles a multi-event key sequence by looking in several keymaps, one by one, for a binding of the whole key sequence. First it checks the minor mode keymaps for minor modes that are enabled, then it checks the major mode's keymap, and then it checks the global keymap. This is not precisely how key lookup works, but it's good enough for understanding ordinary circumstances. To change the local bindings of a major mode, you must change the mode's local keymap. Normally you must wait until the first time the mode is used, because most major modes don't create their keymaps until then. If you want to specify something in your `~/.emacs' file to change a major mode's bindings, you must use the mode's mode hook to delay the change until the mode is first used. For example, the command `texinfo-mode' to select Texinfo mode runs the hook `texinfo-mode-hook'. Here's how you can use the hook to add local bindings (not very useful, we admit) for `C-c n' and `C-c p' in Texinfo mode: (add-hook 'texinfo-mode-hook '(lambda () (define-key texinfo-mode-map "\C-cp" 'backward-paragraph) (define-key texinfo-mode-map "\C-cn" 'forward-paragraph) )) *Note Hooks::.  File: emacs, Node: Minibuffer Maps, Next: Rebinding, Prev: Local Keymaps, Up: Key Bindings Minibuffer Keymaps ------------------ The minibuffer has its own set of local keymaps; they contain various completion and exit commands. * `minibuffer-local-map' is used for ordinary input (no completion). * `minibuffer-local-ns-map' is similar, except that SPC exits just like RET. This is used mainly for Mocklisp compatibility. * `minibuffer-local-completion-map' is for permissive completion. * `minibuffer-local-must-match-map' is for strict completion and for cautious completion.  File: emacs, Node: Rebinding, Next: Init Rebinding, Prev: Minibuffer Maps, Up: Key Bindings Changing Key Bindings Interactively ----------------------------------- The way to redefine an Emacs key is to change its entry in a keymap. You can change the global keymap, in which case the change is effective in all major modes (except those that have their own overriding local definitions for the same key). Or you can change the current buffer's local map, which affects all buffers using the same major mode. `M-x global-set-key RET KEY CMD RET' Define KEY globally to run CMD. `M-x local-set-key RET KEY CMD RET' Define KEY locally (in the major mode now in effect) to run CMD. `M-x global-unset-key RET KEY' Make KEY undefined in the global map. `M-x local-unset-key RET KEY' Make KEY undefined locally (in the major mode now in effect). For example, suppose you like to execute commands in a subshell within an Emacs buffer, instead of suspending Emacs and executing commands in your login shell. Normally, `C-z' is bound to the function `suspend-emacs' (when not using the X Window System), but you can change `C-z' to invoke an interactive subshell within Emacs, by binding it to `shell' as follows: M-x global-set-key RET C-z shell RET `global-set-key' reads the command name after the key. After you press the key, a message like this appears so that you can confirm that you are binding the key you want: Set key C-z to command: You can redefine function keys and mouse events in the same way; just type the function key or click the mouse when it's time to specify the key to rebind. You can rebind a key that contains more than one event in the same way. Emacs keeps reading the key to rebind until it is a complete key (that is, not a prefix key). Thus, if you type `C-f' for KEY, that's the end; the minibuffer is entered immediately to read CMD. But if you type `C-x', another character is read; if that is `4', another character is read, and so on. For example, M-x global-set-key RET C-x 4 $ spell-other-window RET redefines `C-x 4 $' to run the (fictitious) command `spell-other-window'. The two-character keys consisting of `C-c' followed by a letter are reserved for user customizations. Lisp programs are not supposed to define these keys, so the bindings you make for them will be available in all major modes and will never get in the way of anything. You can remove the global definition of a key with `global-unset-key'. This makes the key "undefined"; if you type it, Emacs will just beep. Similarly, `local-unset-key' makes a key undefined in the current major mode keymap, which makes the global definition (or lack of one) come back into effect in that major mode. If you have redefined (or undefined) a key and you subsequently wish to retract the change, undefining the key will not do the job--you need to redefine the key with its standard definition. To find the name of the standard definition of a key, go to a Fundamental mode buffer and use `C-h c'. The documentation of keys in this manual also lists their command names. If you want to prevent yourself from invoking a command by mistake, it is better to disable the command than to undefine the key. A disabled command is less work to invoke when you really want to. *Note Disabling::.  File: emacs, Node: Init Rebinding, Next: Function Keys, Prev: Rebinding, Up: Key Bindings Rebinding Keys in Your Init File -------------------------------- If you have a set of key bindings that you like to use all the time, you can specify them in your `.emacs' file by using their Lisp syntax. The simplest method for doing this works for ASCII characters and Meta-modified ASCII characters only. This method uses a string to represent the key sequence you want to rebind. For example, here's how to bind `C-z' to `shell': (global-set-key "\C-z" 'shell) This example uses a string constant containing one character, `C-z'. The single-quote before the command name, `shell', marks it as a constant symbol rather than a variable. If you omit the quote, Emacs would try to evaluate `shell' immediately as a variable. This probably causes an error; it certainly isn't what you want. Here is another example that binds a key sequence two characters long: (global-set-key "\C-xl" 'make-symbolic-link) When the key sequence includes function keys or mouse button events, or non-ASCII characters such as `C-=' or `H-a', you must use the more general method of rebinding, which uses a vector to specify the key sequence. The way to write a vector in Emacs Lisp is with square brackets around the vector elements. Use spaces to separate the elements. If an element is a symbol, simply write the symbol's name--no other delimiters or punctuation are needed. If a vector element is a character, write it as a Lisp character constant: `?' followed by the character as it would appear in a string. Here are examples of using vectors to rebind `C-=' (a control character outside of ASCII), `H-a' (a Hyper character; ASCII doesn't have Hyper at all); f7 (a function key), and `C-Mouse-1' (a keyboard-modified mouse button): (global-set-key [?\C-=] 'make-symbolic-link) (global-set-key [?\H-a] 'make-symbolic-link) (global-set-key [f7] 'make-symbolic-link) (global-set-key [C-mouse-1] 'make-symbolic-link) You can use a vector for the simple cases too. Here's how to rewrite the first two examples, above, to use vectors: (global-set-key [?\C-z] 'shell) (global-set-key [?\C-x ?l] 'make-symbolic-link)  File: emacs, Node: Function Keys, Next: Named ASCII Chars, Prev: Init Rebinding, Up: Key Bindings Rebinding Function Keys ----------------------- Key sequences can contain function keys as well as ordinary characters. Just as Lisp characters (actually integers) represent keyboard characters, Lisp symbols represent function keys. If the function key has a word as its label, then that word is also the name of the corresponding Lisp symbol. Here are the conventional Lisp names for common function keys: `left', `up', `right', `down' Cursor arrow keys. `begin', `end', `home', `next', `prior' Other cursor repositioning keys. `select', `print', `execute', `backtab' `insert', `undo', `redo', `clearline' `insertline', `deleteline', `insertchar', `deletechar', Miscellaneous function keys. `f1', `f2', ... `f35' Numbered function keys (across the top of the keyboard). `kp-add', `kp-subtract', `kp-multiply', `kp-divide' `kp-backtab', `kp-space', `kp-tab', `kp-enter' `kp-separator', `kp-decimal', `kp-equal' Keypad keys (to the right of the regular keyboard), with names or punctuation. `kp-0', `kp-1', ... `kp-9' Keypad keys with digits. `kp-f1', `kp-f2', `kp-f3', `kp-f4' Keypad PF keys. These names are conventional, but some systems (especially when using X windows) may use different names. To make certain what symbol is used for a given function key on your terminal, type `C-h c' followed by that key. A key sequence which contains function key symbols (or anything but ASCII characters) must be a vector rather than a string. The vector syntax uses spaces between the elements, and square brackets around the whole vector. Thus, to bind function key `f1' to the command `rmail', write the following: (global-set-key [f1] 'rmail) To bind the right-arrow key to the command `forward-char', you can use this expression: (global-set-key [right] 'forward-char) This uses the Lisp syntax for a vector containing the symbol `right'. (This binding is present in Emacs by default.) *Note Init Rebinding::, for more information about using vectors for rebinding. You can mix function keys and characters in a key sequence. This example binds `C-x NEXT' to the command `forward-page'. (global-set-key [?\C-x next] 'forward-page) where `?\C-x' is the Lisp character constant for the character `C-x'. The vector element `next' is a symbol and therefore does not take a question mark. You can use the modifier keys CTRL, META, HYPER, SUPER, ALT and SHIFT with function keys. To represent these modifiers, add the strings `C-', `M-', `H-', `s-', `A-' and `S-' at the front of the symbol name. Thus, here is how to make `Hyper-Meta-RIGHT' move forward a word: (global-set-key [H-M-right] 'forward-word)  File: emacs, Node: Named ASCII Chars, Next: Mouse Buttons, Prev: Function Keys, Up: Key Bindings Named ASCII Control Characters ------------------------------ TAB, RET, BS, LFD, ESC and DEL started out as names for certain ASCII control characters, used so often that they have special keys of their own. Later, users found it convenient to distinguish in Emacs between these keys and the "same" control characters typed with the CTRL key. Emacs distinguishes these two kinds of input, when used with the X Window System. It treats the "special" keys as function keys named `tab', `return', `backspace', `linefeed', `escape', and `delete'. These function keys translate automatically into the corresponding ASCII characters *if* they have no bindings of their own. As a result, neither users nor Lisp programs need to pay attention to the distinction unless they care to. If you do not want to distinguish between (for example) TAB and `C-i', make just one binding, for the ASCII character TAB (octal code 011). If you do want to distinguish, make one binding for this ASCII character, and another for the "function key" `tab'. With an ordinary ASCII terminal, there is no way to distinguish between TAB and `C-i' (and likewise for other such pairs), because the terminal sends the same character in both cases.  File: emacs, Node: Mouse Buttons, Next: Disabling, Prev: Named ASCII Chars, Up: Key Bindings Rebinding Mouse Buttons ----------------------- Emacs uses Lisp symbols to designate mouse buttons, too. The ordinary mouse events in Emacs are "click" events; these happen when you press a button and release it without moving the mouse. You can also get "drag" events, when you move the mouse while holding the button down. Drag events happen when you finally let go of the button. The symbols for basic click events are `mouse-1' for the leftmost button, `mouse-2' for the next, and so on. Here is how you can redefine the second mouse button to split the current window: (global-set-key [mouse-2] 'split-window-vertically) The symbols for drag events are similar, but have the prefix `drag-' before the word `mouse'. For example, dragging the first button generates a `drag-mouse-1' event. You can also define bindings for events that occur when a mouse button is pressed down. These events start with `down-' instead of `drag-'. Such events are generated only if they have key bindings. When you get a button-down event, a corresponding click or drag event will always follow. If you wish, you can distinguish single, double, and triple clicks. A double click means clicking a mouse button twice in approximately the same place. The first click generates an ordinary click event. The second click, if it comes soon enough, generates a double-click event instead. The event type for a double-click event starts with `double-': for example, `double-mouse-3'. This means that you can give a special meaning to the second click at the same place, but it must act on the assumption that the ordinary single click definition has run when the first click was received. This constrains what you can do with double clicks, but user interface designers say that this constraint ought to be followed in any case. A double click should do something similar to the single click, only "more so." The command for the double-click event should perform the extra work for the double click. If a double-click event has no binding, it changes to the corresponding single-click event. Thus, if you don't define a particular double click specially, it executes the single-click command twice. Emacs also supports triple-click events whose names start with `triple-'. Emacs does not distinguish quadruple clicks as event types; clicks beyond the third generate additional triple-click events. However, the full number of clicks is recorded in the event list, so you can distinguish if you really want to. We don't recommend distinct meanings for more than three clicks, but sometimes it is useful for subsequent clicks to cycle through the same set of three meanings, so that four clicks are equivalent to one click, five are equivalent to two, and six are equivalent to three. Emacs also records multiple presses in drag and button-down events. For example, when you press a button twice, then move the mouse while holding the button, Emacs gets a `double-drag-' event. And at the moment when you press it down for the second time, Emacs gets a `double-down-' event (which is ignored, like all button-down events, if it has no binding). The variable `double-click-time' specifies how long may elapse between clicks that are recognized as a pair. Its value is measured in milliseconds. If the value is `nil', double clicks are not detected at all. If the value is `t', then there is no time limit. The symbols for mouse events also indicate the status of the modifier keys, with the usual prefixes `C-', `M-', `H-', `s-', `A-' and `S-'. These always precede `double-' or `triple-', which always precede `drag-' or `down-'. A frame includes areas that don't show text from the buffer, such as the mode line and the scroll bar. You can tell whether a mouse button comes from a special area of the screen by means of dummy "prefix keys." For example, if you click the mouse in the mode line, you get the prefix key `mode-line' before the ordinary mouse-button symbol. Thus, here is how to define the command for clicking the first button in a mode line to run `scroll-up': (global-set-key [mode-line mouse-1] 'scroll-up) Here is the complete list of these dummy prefix keys and their meanings: `mode-line' The mouse was in the mode line of a window. `vertical-line' The mouse was in the vertical line separating side-by-side windows. (If you use scroll bars, they appear in place of these vertical lines.) `vertical-scroll-bar' The mouse was in a vertical scroll bar. (This is the only kind of scroll bar Emacs currently supports.) You can put more than one mouse button in a key sequence, but it isn't usual to do so.  File: emacs, Node: Disabling, Prev: Mouse Buttons, Up: Key Bindings Disabling Commands ------------------ Disabling a command marks the command as requiring confirmation before it can be executed. The purpose of disabling a command is to prevent beginning users from executing it by accident and being confused. An attempt to invoke a disabled command interactively in Emacs displays a window containing the command's name, its documentation, and some instructions on what to do immediately; then Emacs asks for input saying whether to execute the command as requested, enable it and execute it, or cancel. If you decide to enable the command, you are asked whether to do this permanently or just for the current session. Enabling permanently works by automatically editing your `.emacs' file. The direct mechanism for disabling a command is to put a non-`nil' `disabled' property on the Lisp symbol for the command. Here is the Lisp program to do this: (put 'delete-region 'disabled t) If the value of the `disabled' property is a string, that string is included in the message printed when the command is used: (put 'delete-region 'disabled "It's better to use `kill-region' instead.\n") You can make a command disabled either by editing the `.emacs' file directly or with the command `M-x disable-command', which edits the `.emacs' file for you. Likewise, `M-x enable-command' edits `.emacs' to enable a command permanently. *Note Init File::. Whether a command is disabled is independent of what key is used to invoke it; disabling also applies if the command is invoked using `M-x'. Disabling a command has no effect on calling it as a function from Lisp programs.  File: emacs, Node: Keyboard Translations, Next: Syntax, Prev: Key Bindings, Up: Customization Keyboard Translations ===================== Some keyboards do not make it convenient to send all the special characters that Emacs uses. The most common problem case is the DEL character. Some keyboards provide no convenient way to type this very important character--usually because they were designed to expect the character `C-h' to be used for deletion. On these keyboards, if you press the key normally used for deletion, Emacs handles the `C-h' as a prefix character and offers you a list of help options, which is not what you want. You can work around this problem within Emacs by setting up keyboard translations to turn `C-h' into DEL and DEL into `C-h', as follows: ;; Translate `C-h' to DEL. (keyboard-translate ?\C-h ?\C-?) ;; Translate DEL to `C-h'. (keyboard-translate ?\C-? ?\C-h) Keyboard translations are not the same as key bindings in keymaps (*note Keymaps::.). Emacs contains numerous keymaps that apply in different situations, but there is only one set of keyboard translations, and it applies to every character that Emacs reads from the terminal. Keyboard translations take place at the lowest level of input processing; the keys that are looked up in keymaps contain the characters that result from keyboard translation. Under X, the keyboard key named DELETE is a function key and is distinct from the ASCII character named DEL. *Note Named ASCII Chars::. Keyboard translations affect only ASCII character input, not function keys; thus, the above example used under X does not affect the DELETE key. However, the translation above isn't necessary under X, because Emacs can also distinguish between the BACKSPACE key and `C-h'; and it normally treats BACKSPACE as DEL. For full information about how to use keyboard translations, see *Note Translating Input: (elisp)Translating Input.  File: emacs, Node: Syntax, Next: Init File, Prev: Keyboard Translations, Up: Customization The Syntax Table ================ All the Emacs commands which parse words or balance parentheses are controlled by the "syntax table". The syntax table says which characters are opening delimiters, which are parts of words, which are string quotes, and so on. Each major mode has its own syntax table (though sometimes related major modes use the same one) which it installs in each buffer that uses that major mode. The syntax table installed in the current buffer is the one that all commands use, so we call it "the" syntax table. A syntax table is a Lisp object, a char-table, whose elements are numbers. To display a description of the contents of the current syntax table, type `C-h s' (`describe-syntax'). The description of each character includes both the string you would have to give to `modify-syntax-entry' to set up that character's current syntax, and some English to explain that string if necessary. For full information on the syntax table, see *Note Syntax Tables: (elisp)Syntax Tables.  File: emacs, Node: Init File, Prev: Syntax, Up: Customization The Init File, `~/.emacs' ========================= When Emacs is started, it normally loads a Lisp program from the file `.emacs' in your home directory. We call this file your "init file" because it specifies how to initialize Emacs for you. You can use the command line switch `-q' to prevent loading your init file, and `-u' (or `--user') to specify a different user's init file (*note Entering Emacs::.). There can also be a "default init file", which is the library named `default.el', found via the standard search path for libraries. The Emacs distribution contains no such library; your site may create one for local customizations. If this library exists, it is loaded whenever you start Emacs (except when you specify `-q'). But your init file, if any, is loaded first; if it sets `inhibit-default-init' non-`nil', then `default' is not loaded. Your site may also have a "site startup file"; this is named `site-start.el', if it exists. Emacs loads this library before it loads your init file. To inhibit loading of this library, use the option `-no-site-file'. If you have a large amount of code in your `.emacs' file, you should move it into another file such as `~/SOMETHING.el', byte-compile it, and make your `.emacs' file load it with `(load "~/SOMETHING")'. *Note Byte Compilation: (elisp)Byte Compilation, for more information about compiling Emacs Lisp programs. If you are going to write actual Emacs Lisp programs that go beyond minor customization, you should read the `Emacs Lisp Reference Manual'. *Note Emacs Lisp: (elisp)Top. * Menu: * Init Syntax:: Syntax of constants in Emacs Lisp. * Init Examples:: How to do some things with an init file. * Terminal Init:: Each terminal type can have an init file. * Find Init:: How Emacs finds the init file.  File: emacs, Node: Init Syntax, Next: Init Examples, Up: Init File Init File Syntax ---------------- The `.emacs' file contains one or more Lisp function call expressions. Each of these consists of a function name followed by arguments, all surrounded by parentheses. For example, `(setq fill-column 60)' calls the function `setq' to set the variable `fill-column' (*note Filling::.) to 60. The second argument to `setq' is an expression for the new value of the variable. This can be a constant, a variable, or a function call expression. In `.emacs', constants are used most of the time. They can be: Numbers: Numbers are written in decimal, with an optional initial minus sign. Strings: Lisp string syntax is the same as C string syntax with a few extra features. Use a double-quote character to begin and end a string constant. In a string, you can include newlines and special characters literally. But often it is cleaner to use backslash sequences for them: `\n' for newline, `\b' for backspace, `\r' for carriage return, `\t' for tab, `\f' for formfeed (control-L), `\e' for escape, `\\' for a backslash, `\"' for a double-quote, or `\OOO' for the character whose octal code is OOO. Backslash and double-quote are the only characters for which backslash sequences are mandatory. `\C-' can be used as a prefix for a control character, as in `\C-s' for ASCII control-S, and `\M-' can be used as a prefix for a Meta character, as in `\M-a' for `Meta-A' or `\M-\C-a' for `Control-Meta-A'. Characters: Lisp character constant syntax consists of a `?' followed by either a character or an escape sequence starting with `\'. Examples: `?x', `?\n', `?\"', `?\)'. Note that strings and characters are not interchangeable in Lisp; some contexts require one and some contexts require the other. True: `t' stands for `true'. False: `nil' stands for `false'. Other Lisp objects: Write a single-quote (') followed by the Lisp object you want.