This is ../info/emacs, produced by makeinfo version 4.3 from emacs.texi.

   This is the Fourteenth edition of the `GNU Emacs Manual', updated
for Emacs version 21.3.

INFO-DIR-SECTION Emacs
START-INFO-DIR-ENTRY
* Emacs: (emacs).	The extensible self-documenting text editor.
END-INFO-DIR-ENTRY

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   (a) The FSF's Back-Cover Text is: "You have freedom to copy and
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Software Foundation raise funds for GNU development."


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.
(*Note Init File::.)

   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)

   To put <TAB>, <RET>, <ESC>, or <DEL> in the string, you can use the
Emacs Lisp escape sequences, `\t', `\r', `\e', and `\d'.  Here is an
example which binds `C-x <TAB>':

     (global-set-key "\C-x\t" 'indent-rigidly)

   These examples show how to write some other special ASCII characters
in strings for key bindings:

     (global-set-key "\r" 'newline)               ;; <RET>
     (global-set-key "\d" 'delete-backward-char)  ;; <DEL>
     (global-set-key "\C-x\e\e" 'repeat-complex-command)  ;; <ESC>

   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 not in ASCII), `C-M-=' (not in ASCII because `C-=' is not),
`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 [?\M-\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 three examples above, using vectors to bind `C-z',
`C-x l', and `C-x <TAB>':

     (global-set-key [?\C-z] 'shell)
     (global-set-key [?\C-x ?l] 'make-symbolic-link)
     (global-set-key [?\C-x ?\t] 'indent-rigidly)
     (global-set-key [?\r] 'newline)
     (global-set-key [?\d] 'delete-backward-char)
     (global-set-key [?\C-x ?\e ?\e] 'repeat-complex-command)

As you see, you represent a multi-character key sequence with a vector
by listing each of the characters within the square brackets that
delimit the vector.


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) 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: Non-ASCII Rebinding,  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 the keyboard
reports these keys to Emacs.  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: Non-ASCII Rebinding,  Next: Mouse Buttons,  Prev: Named ASCII Chars,  Up: Key Bindings

Non-ASCII Characters on the Keyboard
------------------------------------

   If your keyboard has keys that send non-ASCII characters, such as
accented letters, rebinding these keys is a bit tricky.  There are two
solutions you can use.  One is to specify a keyboard coding system,
using `set-keyboard-coding-system' (*note Specify Coding::).  Then you
can bind these keys in the usual way(1), like this:

     (global-set-key [?CHAR] 'some-function)

Type `C-q' followed by the key you want to bind, to insert CHAR.

   If you don't specify the keyboard coding system, that approach won't
work.  Instead, you need to find out the actual code that the terminal
sends.  The easiest way to do this in Emacs is to create an empty buffer
with `C-x b temp <RET>', make it unibyte with `M-x
toggle-enable-multibyte-characters <RET>', then type the key to insert
the character into this buffer.

   Move point before the character, then type `C-x ='.  This displays a
message in the minibuffer, showing the character code in three ways,
octal, decimal and hexadecimal, all within a set of parentheses.  Use
the second of the three numbers, the decimal one, inside the vector to
bind:

     (global-set-key [DECIMAL-CODE] 'some-function)

   If you bind 8-bit characters like this in your init file, you may
find it convenient to specify that it is unibyte.  *Note Enabling
Multibyte::.

   ---------- Footnotes ----------

   (1) Note that you should avoid the string syntax for binding 8-bit
characters, since they will be interpreted as meta keys.  *Note Strings
of Events: (elisp)Strings of Events.


File: emacs,  Node: Mouse Buttons,  Next: Disabling,  Prev: Non-ASCII Rebinding,  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 much time can elapse
between clicks and still allow them to be grouped as a multiple click.
Its value is in units of 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 default is 500.

   The variable `double-click-fuzz' specifies how much the mouse can
move between clicks still allow them to be grouped as a multiple click.
Its value is in units of pixels on windowed displays and in units of
1/8 of a character cell on text-mode terminals; the default is 3.

   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.)  You can also type `!' to enable _all_ commands, for the current
session only.

   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 displayed 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.

   On a window system, 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 on a window
system does not affect the <DELETE> key.  However, the translation
above isn't necessary on window systems, 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.  It does this by assigning each character to
one of fifteen-odd "syntax classes".  In some cases it specifies some
additional information also.

   Each major mode has its own syntax table (though related major modes
sometimes share one syntax table) which it installs in each buffer that
uses the mode.  The syntax table installed in the current buffer is the
one that all commands use, so we call it "the" syntax table.

   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,
starting with the character which designates its syntax class, plus
some English text to explain its meaning.

   A syntax table is actually a Lisp object, a char-table, whose
elements are cons cells.  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' or `.emacs.el' 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.  Like `default.el', Emacs finds this
file via the standard search path for Lisp libraries.  Emacs loads this
library before it loads your init file.  To inhibit loading of this
library, use the option `-no-site-file'.  *Note Initial Options::.

   You can place `default.el' and `site-start.el' in any of the
directories which Emacs searches for Lisp libraries.  The variable
`load-path' (*note Lisp Libraries::) specifies these directories.  Many
sites put these files in the `site-lisp' subdirectory of the Emacs
installation directory, typically `/usr/local/share/emacs/site-lisp'.

   If you have a large amount of code in your `.emacs' file, you should
rename it to `~/.emacs.el', and byte-compile it.  *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'.

     If you want to include non-ASCII characters in strings in your init
     file, you should consider putting a `-*-coding: CODING-SYSTEM-*-'
     tag on the first line which states the coding system used to save
     your `.emacs', as explained in *Note Recognize Coding::.  This is
     because the defaults for decoding non-ASCII text might not yet be
     set up by the time Emacs reads those parts of your init file which
     use such strings, possibly leading Emacs to decode those strings
     incorrectly.

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.

     *Note Non-ASCII Rebinding::, for information about binding
     commands to keys which send non-ASCII characters.

True:
     `t' stands for `true'.

False:
     `nil' stands for `false'.

Other Lisp objects:
     Write a single-quote (`'') followed by the Lisp object you want.


File: emacs,  Node: Init Examples,  Next: Terminal Init,  Prev: Init Syntax,  Up: Init File

Init File Examples
------------------

   Here are some examples of doing certain commonly desired things with
Lisp expressions:

   * Make <TAB> in C mode just insert a tab if point is in the middle
     of a line.

          (setq c-tab-always-indent nil)

     Here we have a variable whose value is normally `t' for `true' and
     the alternative is `nil' for `false'.

   * Make searches case sensitive by default (in all buffers that do not
     override this).

          (setq-default case-fold-search nil)

     This sets the default value, which is effective in all buffers
     that do not have local values for the variable.  Setting
     `case-fold-search' with `setq' affects only the current buffer's
     local value, which is not what you probably want to do in an init
     file.

   * Specify your own email address, if Emacs can't figure it out
     correctly.

          (setq user-mail-address "coon@yoyodyne.com")

     Various Emacs packages that need your own email address use the
     value of `user-mail-address'.

   * Make Text mode the default mode for new buffers.

          (setq default-major-mode 'text-mode)

     Note that `text-mode' is used because it is the command for
     entering Text mode.  The single-quote before it makes the symbol a
     constant; otherwise, `text-mode' would be treated as a variable
     name.

   * Set up defaults for the Latin-1 character set which supports most
     of the languages of Western Europe.

          (set-language-environment "Latin-1")

   * Turn on Auto Fill mode automatically in Text mode and related
     modes.

          (add-hook 'text-mode-hook
            '(lambda () (auto-fill-mode 1)))

     This shows how to add a hook function to a normal hook variable
     (*note Hooks::).  The function we supply is a list starting with
     `lambda', with a single-quote in front of it to make it a list
     constant rather than an expression.

     It's beyond the scope of this manual to explain Lisp functions,
     but for this example it is enough to know that the effect is to
     execute `(auto-fill-mode 1)' when Text mode is entered.  You can
     replace that with any other expression that you like, or with
     several expressions in a row.

     Emacs comes with a function named `turn-on-auto-fill' whose
     definition is `(lambda () (auto-fill-mode 1))'.  Thus, a simpler
     way to write the above example is as follows:

          (add-hook 'text-mode-hook 'turn-on-auto-fill)

   * Load the installed Lisp library named `foo' (actually a file
     `foo.elc' or `foo.el' in a standard Emacs directory).

          (load "foo")

     When the argument to `load' is a relative file name, not starting
     with `/' or `~', `load' searches the directories in `load-path'
     (*note Lisp Libraries::).

   * Load the compiled Lisp file `foo.elc' from your home directory.

          (load "~/foo.elc")

     Here an absolute file name is used, so no searching is done.

   * Tell Emacs to find the definition for the function `myfunction' by
     loading a Lisp library named `mypackage' (i.e. a file
     `mypackage.elc' or `mypackage.el'):

          (autoload 'myfunction "mypackage" "Do what I say." t)

     Here the string `"Do what I say."' is the function's documentation
     string.  You specify it in the `autoload' definition so it will be
     available for help commands even when the package is not loaded.
     The last argument, `t', indicates that this function is
     interactive; that is, it can be invoked interactively by typing
     `M-x myfunction <RET>' or by binding it to a key.  If the function
     is not interactive, omit the `t' or use `nil'.

   * Rebind the key `C-x l' to run the function `make-symbolic-link'.

          (global-set-key "\C-xl" 'make-symbolic-link)

     or

          (define-key global-map "\C-xl" 'make-symbolic-link)

     Note once again the single-quote used to refer to the symbol
     `make-symbolic-link' instead of its value as a variable.

   * Do the same thing for Lisp mode only.

          (define-key lisp-mode-map "\C-xl" 'make-symbolic-link)

   * Redefine all keys which now run `next-line' in Fundamental mode so
     that they run `forward-line' instead.

          (substitute-key-definition 'next-line 'forward-line
                                     global-map)

   * Make `C-x C-v' undefined.

          (global-unset-key "\C-x\C-v")

     One reason to undefine a key is so that you can make it a prefix.
     Simply defining `C-x C-v ANYTHING' will make `C-x C-v' a prefix,
     but `C-x C-v' must first be freed of its usual non-prefix
     definition.

   * Make `$' have the syntax of punctuation in Text mode.  Note the
     use of a character constant for `$'.

          (modify-syntax-entry ?\$ "." text-mode-syntax-table)

   * Enable the use of the command `narrow-to-region' without
     confirmation.

          (put 'narrow-to-region 'disabled nil)


File: emacs,  Node: Terminal Init,  Next: Find Init,  Prev: Init Examples,  Up: Init File

Terminal-specific Initialization
--------------------------------

   Each terminal type can have a Lisp library to be loaded into Emacs
when it is run on that type of terminal.  For a terminal type named
TERMTYPE, the library is called `term/TERMTYPE' and it is found by
searching the directories `load-path' as usual and trying the suffixes
`.elc' and `.el'.  Normally it appears in the subdirectory `term' of
the directory where most Emacs libraries are kept.

   The usual purpose of the terminal-specific library is to map the
escape sequences used by the terminal's function keys onto more
meaningful names, using `function-key-map'.  See the file
`term/lk201.el' for an example of how this is done.  Many function keys
are mapped automatically according to the information in the Termcap
data base; the terminal-specific library needs to map only the function
keys that Termcap does not specify.

   When the terminal type contains a hyphen, only the part of the name
before the first hyphen is significant in choosing the library name.
Thus, terminal types `aaa-48' and `aaa-30-rv' both use the library
`term/aaa'.  The code in the library can use `(getenv "TERM")' to find
the full terminal type name.

   The library's name is constructed by concatenating the value of the
variable `term-file-prefix' and the terminal type.  Your `.emacs' file
can prevent the loading of the terminal-specific library by setting
`term-file-prefix' to `nil'.

   Emacs runs the hook `term-setup-hook' at the end of initialization,
after both your `.emacs' file and any terminal-specific library have
been read in.  Add hook functions to this hook if you wish to override
part of any of the terminal-specific libraries and to define
initializations for terminals that do not have a library.  *Note
Hooks::.


File: emacs,  Node: Find Init,  Prev: Terminal Init,  Up: Init File

How Emacs Finds Your Init File
------------------------------

   Normally Emacs uses the environment variable `HOME' to find
`.emacs'; that's what `~' means in a file name.  But if you run Emacs
from a shell started by `su', Emacs tries to find your own `.emacs',
not that of the user you are currently pretending to be.  The idea is
that you should get your own editor customizations even if you are
running as the super user.

   More precisely, Emacs first determines which user's init file to use.
It gets the user name from the environment variables `LOGNAME' and
`USER'; if neither of those exists, it uses effective user-ID.  If that
user name matches the real user-ID, then Emacs uses `HOME'; otherwise,
it looks up the home directory corresponding to that user name in the
system's data base of users.


File: emacs,  Node: Quitting,  Next: Lossage,  Prev: Customization,  Up: Top

Quitting and Aborting
=====================

`C-g'
`C-<BREAK> (MS-DOS only)'
     Quit: cancel running or partially typed command.

`C-]'
     Abort innermost recursive editing level and cancel the command
     which invoked it (`abort-recursive-edit').

`<ESC> <ESC> <ESC>'
     Either quit or abort, whichever makes sense
     (`keyboard-escape-quit').

`M-x top-level'
     Abort all recursive editing levels that are currently executing.

`C-x u'
     Cancel a previously made change in the buffer contents (`undo').

   There are two ways of canceling commands which are not finished
executing: "quitting" with `C-g', and "aborting" with `C-]' or `M-x
top-level'.  Quitting cancels a partially typed command or one which is
already running.  Aborting exits a recursive editing level and cancels
the command that invoked the recursive edit.  (*Note Recursive Edit::.)

   Quitting with `C-g' is used for getting rid of a partially typed
command, or a numeric argument that you don't want.  It also stops a
running command in the middle in a relatively safe way, so you can use
it if you accidentally give a command which takes a long time.  In
particular, it is safe to quit out of killing; either your text will
_all_ still be in the buffer, or it will _all_ be in the kill ring (or
maybe both).  Quitting an incremental search does special things
documented under searching; in general, it may take two successive
`C-g' characters to get out of a search (*note Incremental Search::).

   On MS-DOS, the character `C-<BREAK>' serves as a quit character like
`C-g'.  The reason is that it is not feasible, on MS-DOS, to recognize
`C-g' while a command is running, between interactions with the user.
By contrast, it _is_ feasible to recognize `C-<BREAK>' at all times.
*Note MS-DOS Input::.

   `C-g' works by setting the variable `quit-flag' to `t' the instant
`C-g' is typed; Emacs Lisp checks this variable frequently and quits if
it is non-`nil'.  `C-g' is only actually executed as a command if you
type it while Emacs is waiting for input.  In that case, the command it
runs is `keyboard-quit'.

   If you quit with `C-g' a second time before the first `C-g' is
recognized, you activate the "emergency escape" feature and return to
the shell.  *Note Emergency Escape::.

   There may be times when you cannot quit.  When Emacs is waiting for
the operating system to do something, quitting is impossible unless
special pains are taken for the particular system call within Emacs
where the waiting occurs.  We have done this for the system calls that
users are likely to want to quit from, but it's possible you will find
another.  In one very common case--waiting for file input or output
using NFS--Emacs itself knows how to quit, but many NFS implementations
simply do not allow user programs to stop waiting for NFS when the NFS
server is hung.

   Aborting with `C-]' (`abort-recursive-edit') is used to get out of a
recursive editing level and cancel the command which invoked it.
Quitting with `C-g' does not do this, and could not do this, because it
is used to cancel a partially typed command _within_ the recursive
editing level.  Both operations are useful.  For example, if you are in
a recursive edit and type `C-u 8' to enter a numeric argument, you can
cancel that argument with `C-g' and remain in the recursive edit.

   The command `<ESC> <ESC> <ESC>' (`keyboard-escape-quit') can either
quit or abort.  This key was defined because <ESC> is used to "get out"
in many PC programs.  It can cancel a prefix argument, clear a selected
region, or get out of a Query Replace, like `C-g'.  It can get out of
the minibuffer or a recursive edit, like `C-]'.  It can also get out of
splitting the frame into multiple windows, like `C-x 1'.  One thing it
cannot do, however, is stop a command that is running.  That's because
it executes as an ordinary command, and Emacs doesn't notice it until
it is ready for a command.

   The command `M-x top-level' is equivalent to "enough" `C-]' commands
to get you out of all the levels of recursive edits that you are in.
`C-]' gets you out one level at a time, but `M-x top-level' goes out
all levels at once.  Both `C-]' and `M-x top-level' are like all other
commands, and unlike `C-g', in that they take effect only when Emacs is
ready for a command.  `C-]' is an ordinary key and has its meaning only
because of its binding in the keymap.  *Note Recursive Edit::.

   `C-x u' (`undo') is not strictly speaking a way of canceling a
command, but you can think of it as canceling a command that already
finished executing.  *Note Undo::, for more information about the undo
facility.


File: emacs,  Node: Lossage,  Next: Bugs,  Prev: Quitting,  Up: Top

Dealing with Emacs Trouble
==========================

   This section describes various conditions in which Emacs fails to
work normally, and how to recognize them and correct them.  For a list
of additional problems you might encounter, see *Note Bugs and
problems: (efaq)Bugs and problems, and the file `etc/PROBLEMS' in the
Emacs distribution.  Type `C-h F' to read the FAQ; type `C-h P' to read
the `PROBLEMS' file.

* Menu:

* DEL Does Not Delete::  What to do if <DEL> doesn't delete.
* Stuck Recursive::       `[...]' in mode line around the parentheses.
* Screen Garbled::        Garbage on the screen.
* Text Garbled::          Garbage in the text.
* Unasked-for Search::    Spontaneous entry to incremental search.
* Memory Full::           How to cope when you run out of memory.
* After a Crash::         Recovering editing in an Emacs session that crashed.
* Emergency Escape::      Emergency escape---
                            What to do if Emacs stops responding.
* Total Frustration::     When you are at your wits' end.


File: emacs,  Node: DEL Does Not Delete,  Next: Stuck Recursive,  Up: Lossage

If <DEL> Fails to Delete
------------------------

   Every keyboard has a large key, a little ways above the <RET> or
<ENTER> key, which you normally use outside Emacs to erase the last
character that you typed.  We call this key "the usual erasure key".
In Emacs, it is supposed to be equivalent to <DEL>, and when Emacs is
properly configured for your terminal, it translates that key into the
character <DEL>.

   When Emacs starts up using a window system, it determines
automatically which key should be <DEL>.  In some unusual cases Emacs
gets the wrong information from the system.  If the usual erasure key
deletes forwards instead of backwards, that is probably what
happened--Emacs ought to be treating the <DELETE> key as <DEL>, but it
isn't.

   With a window system, if the usual erasure key is labeled
<BACKSPACE> and there is a <DELETE> key elsewhere, but the <DELETE> key
deletes backward instead of forward, that too suggests Emacs got the
wrong information--but in the opposite sense.  It ought to be treating
the <BACKSPACE> key as <DEL>, and treating <DELETE> differently, but it
isn't.

   On a text-only terminal, if you find the usual erasure key prompts
for a Help command, like `Control-h', instead of deleting a character,
it means that key is actually sending the <BS> character.  Emacs ought
to be treating <BS> as <DEL>, but it isn't.

   In all of those cases, the immediate remedy is the same: use the
command `M-x normal-erase-is-backspace-mode'.  This toggles between the
two modes that Emacs supports for handling <DEL>, so if Emacs starts in
the wrong mode, it should switch to the right mode.  On a text-only
terminal, if you want to ask for help when <BS> is treated as <DEL>,
use <F1>; `C-?' may also work, if it sends character code 127.

   To fix the problem automatically for every Emacs session, you can
put one of the following lines into your `.emacs' file (*note Init
File::).  For the first case above, where <DELETE> deletes forwards
instead of backwards, use this line to make <DELETE> act as <DEL>
(resulting in behavior compatible with Emacs 20 and previous versions):

     (normal-erase-is-backspace-mode 0)

For the other two cases, where <BACKSPACE> ought to act as <DEL>, use
this line:

     (normal-erase-is-backspace-mode 1)

   Another way to fix the problem for every Emacs session is to
customize the variable `normal-erase-is-backspace': the value `t'
specifies the mode where <BS> or <BACKSPACE> is <DEL>, and `nil'
specifies the other mode.  *Note Easy Customization::.

   With a window system, it can also happen that the usual erasure key
is labeled <BACKSPACE>, there is a <DELETE> key elsewhere, and both
keys delete forward.  This probably means that someone has redefined
your <BACKSPACE> key as a <DELETE> key.  With X, this is typically done
with a command to the `xmodmap' program when you start the server or
log in.  The most likely motive for this customization was to support
old versions of Emacs, so we recommend you simply remove it now.


File: emacs,  Node: Stuck Recursive,  Next: Screen Garbled,  Prev: DEL Does Not Delete,  Up: Lossage

Recursive Editing Levels
------------------------

   Recursive editing levels are important and useful features of Emacs,
but they can seem like malfunctions to the user who does not understand
them.

   If the mode line has square brackets `[...]' around the parentheses
that contain the names of the major and minor modes, you have entered a
recursive editing level.  If you did not do this on purpose, or if you
don't understand what that means, you should just get out of the
recursive editing level.  To do so, type `M-x top-level'.  This is
called getting back to top level.  *Note Recursive Edit::.


File: emacs,  Node: Screen Garbled,  Next: Text Garbled,  Prev: Stuck Recursive,  Up: Lossage

Garbage on the Screen
---------------------

   If the data on the screen looks wrong, the first thing to do is see
whether the text is really wrong.  Type `C-l' to redisplay the entire
screen.  If the screen appears correct after this, the problem was
entirely in the previous screen update.  (Otherwise, see the following
section.)

   Display updating problems often result from an incorrect termcap
entry for the terminal you are using.  The file `etc/TERMS' in the Emacs
distribution gives the fixes for known problems of this sort.
`INSTALL' contains general advice for these problems in one of its
sections.  Very likely there is simply insufficient padding for certain
display operations.  To investigate the possibility that you have this
sort of problem, try Emacs on another terminal made by a different
manufacturer.  If problems happen frequently on one kind of terminal
but not another kind, it is likely to be a bad termcap entry, though it
could also be due to a bug in Emacs that appears for terminals that
have or that lack specific features.


File: emacs,  Node: Text Garbled,  Next: Unasked-for Search,  Prev: Screen Garbled,  Up: Lossage

Garbage in the Text
-------------------

   If `C-l' shows that the text is wrong, try undoing the changes to it
using `C-x u' until it gets back to a state you consider correct.  Also
try `C-h l' to find out what command you typed to produce the observed
results.

   If a large portion of text appears to be missing at the beginning or
end of the buffer, check for the word `Narrow' in the mode line.  If it
appears, the text you don't see is probably still present, but
temporarily off-limits.  To make it accessible again, type `C-x n w'.
*Note Narrowing::.


File: emacs,  Node: Unasked-for Search,  Next: Memory Full,  Prev: Text Garbled,  Up: Lossage

Spontaneous Entry to Incremental Search
---------------------------------------

   If Emacs spontaneously displays `I-search:' at the bottom of the
screen, it means that the terminal is sending `C-s' and `C-q' according
to the poorly designed xon/xoff "flow control" protocol.

   If this happens to you, your best recourse is to put the terminal in
a mode where it will not use flow control, or give it so much padding
that it will never send a `C-s'.  (One way to increase the amount of
padding is to set the variable `baud-rate' to a larger value.  Its
value is the terminal output speed, measured in the conventional units
of baud.)

   If you don't succeed in turning off flow control, the next best thing
is to tell Emacs to cope with it.  To do this, call the function
`enable-flow-control'.

   Typically there are particular terminal types with which you must use
flow control.  You can conveniently ask for flow control on those
terminal types only, using `enable-flow-control-on'.  For example, if
you find you must use flow control on VT-100 and H19 terminals, put the
following in your `.emacs' file:

     (enable-flow-control-on "vt100" "h19")

   When flow control is enabled, you must type `C-\' to get the effect
of a `C-s', and type `C-^' to get the effect of a `C-q'.  (These
aliases work by means of keyboard translations; see *Note Keyboard
Translations::.)


File: emacs,  Node: Memory Full,  Next: After a Crash,  Prev: Unasked-for Search,  Up: Lossage

Running out of Memory
---------------------

   If you get the error message `Virtual memory exceeded', save your
modified buffers with `C-x s'.  This method of saving them has the
smallest need for additional memory.  Emacs keeps a reserve of memory
which it makes available when this error happens; that should be enough
to enable `C-x s' to complete its work.

   Once you have saved your modified buffers, you can exit this Emacs
job and start another, or you can use `M-x kill-some-buffers' to free
space in the current Emacs job.  If you kill buffers containing a
substantial amount of text, you can safely go on editing.  Emacs refills
its memory reserve automatically when it sees sufficient free space
available, in case you run out of memory another time.

   Do not use `M-x buffer-menu' to save or kill buffers when you run
out of memory, because the buffer menu needs a fair amount of memory
itself, and the reserve supply may not be enough.

