This is ../info/emacs, produced by makeinfo version 4.0 from emacs.texi.
This is the thirteenth edition of the `GNU Emacs Manual', updated
for Emacs version 20.7.
INFO-DIR-SECTION Editors
START-INFO-DIR-ENTRY
* Emacs: (emacs). The extensible self-documenting text editor.
END-INFO-DIR-ENTRY
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,
1999 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
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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.
File: emacs, Node: Glossary, Next: Key Index, Prev: Intro, Up: Top
Glossary
********
Abbrev
An abbrev is a text string which expands into a different text
string when present in the buffer. For example, you might define
a few letters as an abbrev for a long phrase that you want to
insert frequently. *Note Abbrevs::.
Aborting
Aborting means getting out of a recursive edit (q.v.). The
commands `C-]' and `M-x top-level' are used for this. *Note
Quitting::.
Alt
Alt is the name of a modifier bit which a keyboard input character
may have. To make a character Alt, type it while holding down the
<ALT> key. Such characters are given names that start with `Alt-'
(usually written `A-' for short). (Note that many terminals have a
key labeled <ALT> which is really a <META> key.) *Note Alt: User
Input.
ASCII character
An ASCII character is either an ASCII control character or an ASCII
printing character. *Note User Input::.
ASCII control character
An ASCII control character is the Control version of an upper-case
letter, or the Control version of one of the characters `@[\]^_?'.
ASCII printing character
ASCII printing characters include letters, digits, space, and these
punctuation characters: `!@#$%^& *()_-+=|\~` {}[]:;"' <>,.?/'.
Auto Fill Mode
Auto Fill mode is a minor mode in which text that you insert is
automatically broken into lines of fixed width. *Note Filling::.
Auto Saving
Auto saving is the practice of saving the contents of an Emacs
buffer in a specially-named file, so that the information will not
be lost if the buffer is lost due to a system error or user error.
*Note Auto Save::.
Backup File
A backup file records the contents that a file had before the
current editing session. Emacs makes backup files automatically
to help you track down or cancel changes you later regret making.
*Note Backup::.
Balance Parentheses
Emacs can balance parentheses manually or automatically. Manual
balancing is done by the commands to move over balanced expressions
(*note Lists::). Automatic balancing is done by blinking or
highlighting the parenthesis that matches one just inserted (*note
Matching Parens: Matching.).
Bind
To bind a key sequence means to give it a binding (q.v.). *Note
Rebinding::.
Binding
A key sequence gets its meaning in Emacs by having a binding,
which is a command (q.v.), a Lisp function that is run when the
user types that sequence. *Note Binding: Commands. Customization
often involves rebinding a character to a different command
function. The bindings of all key sequences are recorded in the
keymaps (q.v.). *Note Keymaps::.
Blank Lines
Blank lines are lines that contain only whitespace. Emacs has
several commands for operating on the blank lines in the buffer.
Buffer
The buffer is the basic editing unit; one buffer corresponds to
one text being edited. You can have several buffers, but at any
time you are editing only one, the `selected' buffer, though
several can be visible when you are using multiple windows (q.v.).
Most buffers are visiting (q.v.) some file. *Note Buffers::.
Buffer Selection History
Emacs keeps a buffer selection history which records how recently
each Emacs buffer has been selected. This is used for choosing a
buffer to select. *Note Buffers::.
Button Down Event
A button down event is the kind of input event generated right
away when you press a mouse button. *Note Mouse Buttons::.
`C-'
`C-' in the name of a character is an abbreviation for Control.
*Note C-: User Input.
`C-M-'
`C-M-' in the name of a character is an abbreviation for
Control-Meta. *Note C-M-: User Input.
Case Conversion
Case conversion means changing text from upper case to lower case
or vice versa. *Note Case::, for the commands for case conversion.
Character
Characters form the contents of an Emacs buffer; see *Note Text
Characters::. Also, key sequences (q.v.) are usually made up of
characters (though they may include other input events as well).
*Note User Input::.
Character Set
Emacs supports a number of character sets, each of which
represents a particular alphabet or script. *Note International::.
Click Event
A click event is the kind of input event generated when you press a
mouse button and release it without moving the mouse. *Note Mouse
Buttons::.
Coding System
A coding system is an encoding for representing text characters in
a file or in a stream of information. Emacs has the ability to
convert text to or from a variety of coding systems when reading
or writing it. *Note Coding Systems::.
Command
A command is a Lisp function specially defined to be able to serve
as a key binding in Emacs. When you type a key sequence (q.v.),
its binding (q.v.) is looked up in the relevant keymaps (q.v.) to
find the command to run. *Note Commands::.
Command Name
A command name is the name of a Lisp symbol which is a command
(*note Commands::). You can invoke any command by its name using
`M-x' (*note M-x::).
Comment
A comment is text in a program which is intended only for humans
reading the program, and which is marked specially so that it will
be ignored when the program is loaded or compiled. Emacs offers
special commands for creating, aligning and killing comments.
*Note Comments::.
Compilation
Compilation is the process of creating an executable program from
source code. Emacs has commands for compiling files of Emacs Lisp
code (*note Byte Compilation: (elisp)Byte Compilation.) and
programs in C and other languages (*note Compilation::).
Complete Key
A complete key is a key sequence which fully specifies one action
to be performed by Emacs. For example, `X' and `C-f' and `C-x m'
are complete keys. Complete keys derive their meanings from being
bound (q.v.) to commands (q.v.). Thus, `X' is conventionally
bound to a command to insert `X' in the buffer; `C-x m' is
conventionally bound to a command to begin composing a mail
message. *Note Keys::.
Completion
Completion is what Emacs does when it automatically fills out an
abbreviation for a name into the entire name. Completion is done
for minibuffer (q.v.) arguments when the set of possible valid
inputs is known; for example, on command names, buffer names, and
file names. Completion occurs when <TAB>, <SPC> or <RET> is
typed. *Note Completion::.
Continuation Line
When a line of text is longer than the width of the window, it
takes up more than one screen line when displayed. We say that the
text line is continued, and all screen lines used for it after the
first are called continuation lines. *Note Continuation: Basic.
Control Character
A control character is a character that you type by holding down
the <CTRL> key. Some control characters also have their own keys,
so that you can type them without using <CTRL>. For example,
<RET>, <TAB>, <ESC> and <DEL> are all control characters. *Note
User Input::.
Copyleft
A copyleft is a notice giving the public legal permission to
redistribute a program or other work of art. Copylefts are used by
left-wing programmers to promote freedom and cooperation, just as
copyrights are used by right-wing programmers to gain power over
other people.
The particular form of copyleft used by the GNU project is called
the GNU General Public License. *Note Copying::.
Current Buffer
The current buffer in Emacs is the Emacs buffer on which most
editing commands operate. You can select any Emacs buffer as the
current one. *Note Buffers::.
Current Line
The line point is on (*note Point::).
Current Paragraph
The paragraph that point is in. If point is between paragraphs,
the current paragraph is the one that follows point. *Note
Paragraphs::.
Current Defun
The defun (q.v.) that point is in. If point is between defuns, the
current defun is the one that follows point. *Note Defuns::.
Cursor
The cursor is the rectangle on the screen which indicates the
position called point (q.v.) at which insertion and deletion takes
place. The cursor is on or under the character that follows
point. Often people speak of `the cursor' when, strictly
speaking, they mean `point'. *Note Cursor: Basic.
Customization
Customization is making minor changes in the way Emacs works. It
is often done by setting variables (*note Variables::) or by
rebinding key sequences (*note Keymaps::).
Default Argument
The default for an argument is the value that will be assumed if
you do not specify one. When the minibuffer is used to read an
argument, the default argument is used if you just type <RET>.
*Note Minibuffer::.
Default Directory
When you specify a file name that does not start with `/' or `~',
it is interpreted relative to the current buffer's default
directory. *Note Default Directory: Minibuffer File.
Defun
A defun is a list at the top level of parenthesis or bracket
structure in a program. It is so named because most such lists in
Lisp programs are calls to the Lisp function `defun'. *Note
Defuns::.
<DEL>
<DEL> is a character that runs the command to delete one character
of text. *Note DEL: Basic.
Deletion
Deletion means erasing text without copying it into the kill ring
(q.v.). The alternative is killing (q.v.). *Note Deletion:
Killing.
Deletion of Files
Deleting a file means erasing it from the file system. *Note Misc
File Ops::.
Deletion of Messages
Deleting a message means flagging it to be eliminated from your
mail file. Until you expunge (q.v.) the Rmail file, you can still
undelete the messages you have deleted. *Note Rmail Deletion::.
Deletion of Windows
Deleting a window means eliminating it from the screen. Other
windows expand to use up the space. The deleted window can never
come back, but no actual text is thereby lost. *Note Windows::.
Directory
File directories are named collections in the file system, within
which you can place individual files or subdirectories. *Note
Directories::.
Dired
Dired is the Emacs facility that displays the contents of a file
directory and allows you to "edit the directory," performing
operations on the files in the directory. *Note Dired::.
Disabled Command
A disabled command is one that you may not run without special
confirmation. The usual reason for disabling a command is that it
is confusing for beginning users. *Note Disabling::.
Down Event
Short for `button down event'.
Drag Event
A drag event is the kind of input event generated when you press a
mouse button, move the mouse, and then release the button. *Note
Mouse Buttons::.
Dribble File
A file into which Emacs writes all the characters that the user
types on the keyboard. Dribble files are used to make a record for
debugging Emacs bugs. Emacs does not make a dribble file unless
you tell it to. *Note Bugs::.
Echo Area
The echo area is the bottom line of the screen, used for echoing
the arguments to commands, for asking questions, and printing
brief messages (including error messages). The messages are
stored in the buffer `*Messages*' so you can review them later.
*Note Echo Area::.
Echoing
Echoing is acknowledging the receipt of commands by displaying
them (in the echo area). Emacs never echoes single-character key
sequences; longer key sequences echo only if you pause while
typing them.
Electric
We say that a character is electric if it is normally
self-inserting (q.v.), but the current major mode (q.v.) redefines
it to do something else as well. For example, some programming
language major modes define particular delimiter characters to
reindent the line or insert one or more newlines in addition to
self-insertion.
Error
An error occurs when an Emacs command cannot execute in the current
circumstances. When an error occurs, execution of the command
stops (unless the command has been programmed to do otherwise) and
Emacs reports the error by printing an error message (q.v.).
Type-ahead is discarded. Then Emacs is ready to read another
editing command.
Error Message
An error message is a single line of output displayed by Emacs
when the user asks for something impossible to do (such as,
killing text forward when point is at the end of the buffer).
They appear in the echo area, accompanied by a beep.
<ESC>
<ESC> is a character used as a prefix for typing Meta characters on
keyboards lacking a <META> key. Unlike the <META> key (which,
like the <SHIFT> key, is held down while another character is
typed), you press the <ESC> key as you would press a letter key,
and it applies to the next character you type.
Expunging
Expunging an Rmail file or Dired buffer is an operation that truly
discards the messages or files you have previously flagged for
deletion.
File Locking
Emacs used file locking to notice when two different users start
to edit one file at the same time. *Note Interlocking::.
File Name
A file name is a name that refers to a file. File names may be
relative or absolute; the meaning of a relative file name depends
on the current directory, but an absolute file name refers to the
same file regardless of which directory is current. On GNU and
Unix systems, an absolute file name starts with a slash (the root
directory) or with `~/' or `~USER/' (a home directory).
Some people use the term "pathname" for file names, but we do not;
we use the word "path" only in the term "search path" (q.v.).
File-Name Component
A file-name component names a file directly within a particular
directory. On GNU and Unix systems, a file name is a sequence of
file-name components, separated by slashes. For example, `foo/bar'
is a file name containing two components, `foo' and `bar'; it
refers to the file named `bar' in the directory named `foo' in the
current directory.
Fill Prefix
The fill prefix is a string that should be expected at the
beginning of each line when filling is done. It is not regarded
as part of the text to be filled. *Note Filling::.
Filling
Filling text means shifting text between consecutive lines so that
all the lines are approximately the same length. *Note Filling::.
Formatted Text
Formatted text is text that displays with formatting information
while you edit. Formatting information includes fonts, colors,
and specified margins. *Note Formatted Text::.
Frame
A frame is a rectangular cluster of Emacs windows. Emacs starts
out with one frame, but you can create more. You can subdivide
each frame into Emacs windows (q.v.). When you are using X
windows, all the frames can be visible at the same time. *Note
Frames::.
Function Key
A function key is a key on the keyboard that sends input but does
not correspond to any character. *Note Function Keys::.
Global
Global means `independent of the current environment; in effect
throughout Emacs'. It is the opposite of local (q.v.). Particular
examples of the use of `global' appear below.
Global Abbrev
A global definition of an abbrev (q.v.) is effective in all major
modes that do not have local (q.v.) definitions for the same
abbrev. *Note Abbrevs::.
Global Keymap
The global keymap (q.v.) contains key bindings that are in effect
except when overridden by local key bindings in a major mode's
local keymap (q.v.). *Note Keymaps::.
Global Mark Ring
The global mark ring records the series of buffers you have
recently set a mark in. In many cases you can use this to
backtrack through buffers you have been editing in, or in which
you have found tags. *Note Global Mark Ring::.
Global Substitution
Global substitution means replacing each occurrence of one string
by another string through a large amount of text. *Note Replace::.
Global Variable
The global value of a variable (q.v.) takes effect in all buffers
that do not have their own local (q.v.) values for the variable.
*Note Variables::.
Graphic Character
Graphic characters are those assigned pictorial images rather than
just names. All the non-Meta (q.v.) characters except for the
Control (q.v.) characters are graphic characters. These include
letters, digits, punctuation, and spaces; they do not include
<RET> or <ESC>. In Emacs, typing a graphic character inserts that
character (in ordinary editing modes). *Note Basic Editing: Basic.
Highlighting
Highlighting text means displaying it with a different foreground
and/or background color to make it stand out from the rest of the
text in the buffer.
Hardcopy
Hardcopy means printed output. Emacs has commands for making
printed listings of text in Emacs buffers. *Note Hardcopy::.
<HELP>
<HELP> is the Emacs name for `C-h' or <F1>. You can type <HELP>
at any time to ask what options you have, or to ask what any
command does. *Note Help::.
Hyper
Hyper is the name of a modifier bit which a keyboard input
character may have. To make a character Hyper, type it while
holding down the <HYPER> key. Such characters are given names
that start with `Hyper-' (usually written `H-' for short). *Note
Hyper: User Input.
Inbox
An inbox is a file in which mail is delivered by the operating
system. Rmail transfers mail from inboxes to Rmail files (q.v.)
in which the mail is then stored permanently or until explicitly
deleted. *Note Rmail Inbox::.
Indentation
Indentation means blank space at the beginning of a line. Most
programming languages have conventions for using indentation to
illuminate the structure of the program, and Emacs has special
commands to adjust indentation. *Note Indentation::.
Indirect Buffer
An indirect buffer is a buffer that shares the text of another
buffer, called its base buffer. *Note Indirect Buffers::.
Input Event
An input event represents, within Emacs, one action taken by the
user on the terminal. Input events include typing characters,
typing function keys, pressing or releasing mouse buttons, and
switching between Emacs frames. *Note User Input::.
Input Method
An input method is a system for entering non-ASCII text characters
by typing sequences of ASCII characters (q.v.). *Note Input
Methods::.
Insertion
Insertion means copying text into the buffer, either from the
keyboard or from some other place in Emacs.
Interlocking
Interlocking is a feature for warning when you start to alter a
file that someone else is already editing. *Note Simultaneous
Editing: Interlocking.
Justification
Justification means adding extra spaces to lines of text to make
them come exactly to a specified width. *Note Justification:
Filling.
Keyboard Macro
Keyboard macros are a way of defining new Emacs commands from
sequences of existing ones, with no need to write a Lisp program.
*Note Keyboard Macros::.
Key Sequence
A key sequence (key, for short) is a sequence of input events
(q.v.) that are meaningful as a single unit. If the key sequence
is enough to specify one action, it is a complete key (q.v.); if
it is not enough, it is a prefix key (q.v.). *Note Keys::.
Keymap
The keymap is the data structure that records the bindings (q.v.)
of key sequences to the commands that they run. For example, the
global keymap binds the character `C-n' to the command function
`next-line'. *Note Keymaps::.
Keyboard Translation Table
The keyboard translation table is an array that translates the
character codes that come from the terminal into the character
codes that make up key sequences. *Note Keyboard Translations::.
Kill Ring
The kill ring is where all text you have killed recently is saved.
You can reinsert any of the killed text still in the ring; this is
called yanking (q.v.). *Note Yanking::.
Killing
Killing means erasing text and saving it on the kill ring so it
can be yanked (q.v.) later. Some other systems call this
"cutting." Most Emacs commands to erase text do killing, as
opposed to deletion (q.v.). *Note Killing::.
Killing Jobs
Killing a job (such as, an invocation of Emacs) means making it
cease to exist. Any data within it, if not saved in a file, is
lost. *Note Exiting::.
Language Environment
Your choice of language environment specifies defaults for the
input method (q.v.) and coding system (q.v.). *Note Language
Environments::. These defaults are relevant if you edit non-ASCII
text (*note International::).
List
A list is, approximately, a text string beginning with an open
parenthesis and ending with the matching close parenthesis. In C
mode and other non-Lisp modes, groupings surrounded by other kinds
of matched delimiters appropriate to the language, such as braces,
are also considered lists. Emacs has special commands for many
operations on lists. *Note Lists::.
Local
Local means `in effect only in a particular context'; the relevant
kind of context is a particular function execution, a particular
buffer, or a particular major mode. It is the opposite of `global'
(q.v.). Specific uses of `local' in Emacs terminology appear
below.
Local Abbrev
A local abbrev definition is effective only if a particular major
mode is selected. In that major mode, it overrides any global
definition for the same abbrev. *Note Abbrevs::.
Local Keymap
A local keymap is used in a particular major mode; the key bindings
(q.v.) in the current local keymap override global bindings of the
same key sequences. *Note Keymaps::.
Local Variable
A local value of a variable (q.v.) applies to only one buffer.
*Note Locals::.
`M-'
`M-' in the name of a character is an abbreviation for <META>, one
of the modifier keys that can accompany any character. *Note User
Input::.
`M-C-'
`M-C-' in the name of a character is an abbreviation for
Control-Meta; it means the same thing as `C-M-'. If your terminal
lacks a real <META> key, you type a Control-Meta character by
typing <ESC> and then typing the corresponding Control character.
*Note C-M-: User Input.
`M-x'
`M-x' is the key sequence which is used to call an Emacs command by
name. This is how you run commands that are not bound to key
sequences. *Note M-x::.
Mail
Mail means messages sent from one user to another through the
computer system, to be read at the recipient's convenience. Emacs
has commands for composing and sending mail, and for reading and
editing the mail you have received. *Note Sending Mail::. *Note
Rmail::, for how to read mail.
Mail Composition Method
A mail composition method is a program runnable within Emacs for
editing and sending a mail message. Emacs lets you select from
several alternative mail composition methods. *Note Mail
Methods::.
Major Mode
The Emacs major modes are a mutually exclusive set of options,
each of which configures Emacs for editing a certain sort of text.
Ideally, each programming language has its own major mode. *Note
Major Modes::.
Mark
The mark points to a position in the text. It specifies one end
of the region (q.v.), point being the other end. Many commands
operate on all the text from point to the mark. Each buffer has
its own mark. *Note Mark::.
Mark Ring
The mark ring is used to hold several recent previous locations of
the mark, just in case you want to move back to them. Each buffer
has its own mark ring; in addition, there is a single global mark
ring (q.v.). *Note Mark Ring::.
Menu Bar
The menu bar is the line at the top of an Emacs frame. It contains
words you can click on with the mouse to bring up menus. The menu
bar feature is supported only with X. *Note Menu Bars::.
Message
See `mail'.
Meta
Meta is the name of a modifier bit which a command character may
have. It is present in a character if the character is typed with
the <META> key held down. Such characters are given names that
start with `Meta-' (usually written `M-' for short). For example,
`M-<' is typed by holding down <META> and at the same time typing
`<' (which itself is done, on most terminals, by holding down
<SHIFT> and typing `,'). *Note Meta: User Input.
Meta Character
A Meta character is one whose character code includes the Meta bit.
Minibuffer
The minibuffer is the window that appears when necessary inside the
echo area (q.v.), used for reading arguments to commands. *Note
Minibuffer::.
Minibuffer History
The minibuffer history records the text you have specified in the
past for minibuffer arguments, so you can conveniently use the
same text again. *Note Minibuffer History::.
Minor Mode
A minor mode is an optional feature of Emacs which can be switched
on or off independently of all other features. Each minor mode
has a command to turn it on or off. *Note Minor Modes::.
Minor Mode Keymap
A keymap that belongs to a minor mode and is active when that mode
is enabled. Minor mode keymaps take precedence over the buffer's
local keymap, just as the local keymap takes precedence over the
global keymap. *Note Keymaps::.
Mode Line
The mode line is the line at the bottom of each window (q.v.),
giving status information on the buffer displayed in that window.
*Note Mode Line::.
Modified Buffer
A buffer (q.v.) is modified if its text has been changed since the
last time the buffer was saved (or since when it was created, if it
has never been saved). *Note Saving::.
Moving Text
Moving text means erasing it from one place and inserting it in
another. The usual way to move text by killing (q.v.) and then
yanking (q.v.). *Note Killing::.
MULE
MULE refers to the Emacs features for editing non-ASCII text using
multibyte characters (q.v.). *Note International::.
Multibyte Character
A multibyte character is a character that takes up several buffer
positions. Emacs uses multibyte characters to represent non-ASCII
text, since the number of non-ASCII characters is much more than
256. *Note International Intro::.
Named Mark
A named mark is a register (q.v.) in its role of recording a
location in text so that you can move point to that location.
*Note Registers::.
Narrowing
Narrowing means creating a restriction (q.v.) that limits editing
in the current buffer to only a part of the text in the buffer.
Text outside that part is inaccessible to the user until the
boundaries are widened again, but it is still there, and saving
the file saves it all. *Note Narrowing::.
Newline
Control-J characters in the buffer terminate lines of text and are
therefore also called newlines. *Note Newline: Text Characters.
Numeric Argument
A numeric argument is a number, specified before a command, to
change the effect of the command. Often the numeric argument
serves as a repeat count. *Note Arguments::.
Overwrite Mode
Overwrite mode is a minor mode. When it is enabled, ordinary text
characters replace the existing text after point rather than
pushing it to the right. *Note Minor Modes::.
Page
A page is a unit of text, delimited by formfeed characters (ASCII
control-L, code 014) coming at the beginning of a line. Some Emacs
commands are provided for moving over and operating on pages.
*Note Pages::.
Paragraph
Paragraphs are the medium-size unit of English text. There are
special Emacs commands for moving over and operating on paragraphs.
*Note Paragraphs::.
Parsing
We say that certain Emacs commands parse words or expressions in
the text being edited. Really, all they know how to do is find
the other end of a word or expression. *Note Syntax::.
Point
Point is the place in the buffer at which insertion and deletion
occur. Point is considered to be between two characters, not at
one character. The terminal's cursor (q.v.) indicates the
location of point. *Note Point: Basic.
Prefix Argument
See `numeric argument'.
Prefix Key
A prefix key is a key sequence (q.v.) whose sole function is to
introduce a set of longer key sequences. `C-x' is an example of
prefix key; any two-character sequence starting with `C-x' is
therefore a legitimate key sequence. *Note Keys::.
Primary Rmail File
Your primary Rmail file is the file named `RMAIL' in your home
directory. That's where Rmail stores your incoming mail, unless
you specify a different file name. *Note Rmail::.
Primary Selection
The primary selection is one particular X selection (q.v.); it is
the selection that most X applications use for transferring text
to and from other applications.
The Emacs kill commands set the primary selection and the yank
command uses the primary selection when appropriate. *Note
Killing::.
Prompt
A prompt is text printed to ask the user for input. Displaying a
prompt is called prompting. Emacs prompts always appear in the
echo area (q.v.). One kind of prompting happens when the
minibuffer is used to read an argument (*note Minibuffer::); the
echoing which happens when you pause in the middle of typing a
multi-character key sequence is also a kind of prompting (*note
Echo Area::).
Quitting
Quitting means canceling a partially typed command or a running
command, using `C-g' (or `C-<BREAK>' on MS-DOS). *Note Quitting::.
Quoting
Quoting means depriving a character of its usual special
significance. The most common kind of quoting in Emacs is with
`C-q'. What constitutes special significance depends on the
context and on convention. For example, an "ordinary" character
as an Emacs command inserts itself; so in this context, a special
character is any character that does not normally insert itself
(such as <DEL>, for example), and quoting it makes it insert
itself as if it were not special. Not all contexts allow quoting.
*Note Quoting: Basic.
Quoting File Names
Quoting a file name turns off the special significance of
constructs such as `$', `~' and `:'. *Note Quoted File Names::.
Read-Only Buffer
A read-only buffer is one whose text you are not allowed to change.
Normally Emacs makes buffers read-only when they contain text which
has a special significance to Emacs; for example, Dired buffers.
Visiting a file that is write-protected also makes a read-only
buffer. *Note Buffers::.
Rectangle
A rectangle consists of the text in a given range of columns on a
given range of lines. Normally you specify a rectangle by putting
point at one corner and putting the mark at the opposite corner.
*Note Rectangles::.
Recursive Editing Level
A recursive editing level is a state in which part of the
execution of a command involves asking the user to edit some text.
This text may or may not be the same as the text to which the
command was applied. The mode line indicates recursive editing
levels with square brackets (`[' and `]'). *Note Recursive Edit::.
Redisplay
Redisplay is the process of correcting the image on the screen to
correspond to changes that have been made in the text being edited.
*Note Redisplay: Screen.
Regexp
See `regular expression'.
Region
The region is the text between point (q.v.) and the mark (q.v.).
Many commands operate on the text of the region. *Note Region:
Mark.
Registers
Registers are named slots in which text or buffer positions or
rectangles can be saved for later use. *Note Registers::.
Regular Expression
A regular expression is a pattern that can match various text
strings; for example, `l[0-9]+' matches `l' followed by one or more
digits. *Note Regexps::.
Repeat Count
See `numeric argument'.
Replacement
See `global substitution'.
Restriction
A buffer's restriction is the amount of text, at the beginning or
the end of the buffer, that is temporarily inaccessible. Giving a
buffer a nonzero amount of restriction is called narrowing (q.v.).
*Note Narrowing::.
<RET>
<RET> is a character that in Emacs runs the command to insert a
newline into the text. It is also used to terminate most arguments
read in the minibuffer (q.v.). *Note Return: User Input.
Rmail File
An Rmail file is a file containing text in a special format used by
Rmail for storing mail. *Note Rmail::.
Saving
Saving a buffer means copying its text into the file that was
visited (q.v.) in that buffer. This is the way text in files
actually gets changed by your Emacs editing. *Note Saving::.
Scroll Bar
A scroll bar is a tall thin hollow box that appears at the side of
a window. You can use mouse commands in the scroll bar to scroll
the window. The scroll bar feature is supported only with X.
*Note Scroll Bars::.
Scrolling
Scrolling means shifting the text in the Emacs window so as to see
a different part of the buffer. *Note Scrolling: Display.
Searching
Searching means moving point to the next occurrence of a specified
string or the next match for a specified regular expression.
*Note Search::.
Search Path
A search path is a list of directory names, to be used for
searching for files for certain purposes. For example, the
variable `load-path' holds a search path for finding Lisp library
files. *Note Lisp Libraries::.
Secondary Selection
The secondary selection is one particular X selection; some X
applications can use it for transferring text to and from other
applications. Emacs has special mouse commands for transferring
text using the secondary selection. *Note Secondary Selection::.
Selecting
Selecting a buffer means making it the current (q.v.) buffer.
*Note Selecting: Buffers.
Selection
The X window system allows an application program to specify named
selections whose values are text. A program can also read the
selections that other programs have set up. This is the principal
way of transferring text between window applications. Emacs has
commands to work with the primary (q.v.) selection and the
secondary (q.v.) selection.
Self-Documentation
Self-documentation is the feature of Emacs which can tell you what
any command does, or give you a list of all commands related to a
topic you specify. You ask for self-documentation with the help
character, `C-h'. *Note Help::.
Self-Inserting Character
A character is self-inserting if typing that character inserts that
character in the buffer. Ordinary printing and whitespace
characters are self-inserting in Emacs, except in certain special
major modes.
Sentences
Emacs has commands for moving by or killing by sentences. *Note
Sentences::.
Sexp
A sexp (short for `s-expression') is the basic syntactic unit of
Lisp in its textual form: either a list, or Lisp atom. Many Emacs
commands operate on sexps. The term `sexp' is generalized to
languages other than Lisp, to mean a syntactically recognizable
expression. *Note Sexps: Lists.
Simultaneous Editing
Simultaneous editing means two users modifying the same file at
once. Simultaneous editing if not detected can cause one user to
lose his work. Emacs detects all cases of simultaneous editing
and warns one of the users to investigate. *Note Simultaneous
Editing: Interlocking.
String
A string is a kind of Lisp data object which contains a sequence of
characters. Many Emacs variables are intended to have strings as
values. The Lisp syntax for a string consists of the characters
in the string with a `"' before and another `"' after. A `"' that
is part of the string must be written as `\"' and a `\' that is
part of the string must be written as `\\'. All other characters,
including newline, can be included just by writing them inside the
string; however, backslash sequences as in C, such as `\n' for
newline or `\241' using an octal character code, are allowed as
well.
String Substitution
See `global substitution'.
Syntax Table
The syntax table tells Emacs which characters are part of a word,
which characters balance each other like parentheses, etc. *Note
Syntax::.
Super
Super is the name of a modifier bit which a keyboard input
character may have. To make a character Super, type it while
holding down the <SUPER> key. Such characters are given names
that start with `Super-' (usually written `s-' for short). *Note
Super: User Input.
Tags Table
A tags table is a file that serves as an index to the function
definitions in one or more other files. *Note Tags::.
Termscript File
A termscript file contains a record of all characters sent by
Emacs to the terminal. It is used for tracking down bugs in Emacs
redisplay. Emacs does not make a termscript file unless you tell
it to. *Note Bugs::.
Text
Two meanings (*note Text::):
* Data consisting of a sequence of characters, as opposed to
binary numbers, images, graphics commands, executable
programs, and the like. The contents of an Emacs buffer are
always text in this sense.
* Data consisting of written human language, as opposed to
programs, or following the stylistic conventions of human
language.
Top Level
Top level is the normal state of Emacs, in which you are editing
the text of the file you have visited. You are at top level
whenever you are not in a recursive editing level (q.v.) or the
minibuffer (q.v.), and not in the middle of a command. You can
get back to top level by aborting (q.v.) and quitting (q.v.).
*Note Quitting::.
Transposition
Transposing two units of text means putting each one into the place
formerly occupied by the other. There are Emacs commands to
transpose two adjacent characters, words, sexps (q.v.) or lines
(*note Transpose::).
Truncation
Truncating text lines in the display means leaving out any text on
a line that does not fit within the right margin of the window
displaying it. See also `continuation line'. *Note Truncation:
Basic.
Undoing
Undoing means making your previous editing go in reverse, bringing
back the text that existed earlier in the editing session. *Note
Undo::.
User Option
A user option is a variable (q.v.) that exists so that you can
customize Emacs by setting it to a new value. *Note Variables::.
Variable
A variable is an object in Lisp that can store an arbitrary value.
Emacs uses some variables for internal purposes, and has others
(known as `user options' (q.v.)) just so that you can set their
values to control the behavior of Emacs. The variables used in
Emacs that you are likely to be interested in are listed in the
Variables Index in this manual. *Note Variables::, for
information on variables.
Version Control
Version control systems keep track of multiple versions of a
source file. They provide a more powerful alternative to keeping
backup files (q.v.). *Note Version Control::.
Visiting
Visiting a file means loading its contents into a buffer (q.v.)
where they can be edited. *Note Visiting::.
Whitespace
Whitespace is any run of consecutive formatting characters (space,
tab, newline, and backspace).
Widening
Widening is removing any restriction (q.v.) on the current buffer;
it is the opposite of narrowing (q.v.). *Note Narrowing::.
Window
Emacs divides a frame (q.v.) into one or more windows, each of
which can display the contents of one buffer (q.v.) at any time.
*Note Screen::, for basic information on how Emacs uses the screen.
*Note Windows::, for commands to control the use of windows.
Word Abbrev
Synonymous with `abbrev'.
Word Search
Word search is searching for a sequence of words, considering the
punctuation between them as insignificant. *Note Word Search::.
WYSIWYG
WYSIWYG stands for `What you see is what you get.' Emacs generally
provides WYSIWYG editing for files of characters; in Enriched mode
(*note Formatted Text::), it provides WYSIWYG editing for files
that include text formatting information.
Yanking
Yanking means reinserting text previously killed. It can be used
to undo a mistaken kill, or for copying or moving text. Some other
systems call this "pasting." *Note Yanking::.