2 Keystrokes, Key Sequences, and Key Bindings
*********************************************


* Intro to Keystrokes::      Keystrokes as building blocks of key sequences.
* Representing Keystrokes::  Using lists of modifiers and keysyms to
                             represent keystrokes.
* Key Sequences::            Combine key strokes into key sequences you can
                             bind to commands.
* String Key Sequences::     Available for upward compatibility.
* Meta Key::                 Using <ESC> to represent <Meta>
* Super and Hyper Keys::     Adding modifier keys on certain keyboards.
* Character Representation:: How characters appear in Emacs buffers.
* Commands::                 How commands are bound to key sequences.
 
2.1 Keystrokes as Building Blocks of Key Sequences
==================================================

      Earlier versions of Emacs used only the ASCII character set,
which defines 128 different character codes.  Some of these codes are
assigned graphic symbols like `a' and `='; the rest are
control characters, such as Control-a (also called C-a).
C-a means you hold down the <CTRL> key and then press
a.

   Keybindings in XEmacs are not restricted to the set of
keystrokes that can be represented in ASCII.  XEmacs can tell the
difference between, for example, Control-h, Control-Shift-h,
and Backspace.
  

  A keystroke is like a piano chord: you get it by simultaneously
striking several keys.  To be more precise, a keystroke consists
of a possibly empty set of modifiers followed by a single
keysym.  The set of modifiers is small; it consists of
Control, Meta, Super, Hyper, and Shift.

  The rest of the keys on your keyboard, along with the mouse buttons,
make up the set of keysyms.  A keysym is usually what is printed on the
keys on your keyboard.  Here is a table of some of the symbolic names
for keysyms:
a,b,c...
alphabetic keys
f1,f2...
function keys
button1
left mouse button
button2
middle mouse button
button3
right mouse button
button1up
upstroke on the left mouse button
button2up
upstroke on the middle mouse button
button3up
upstroke on the right mouse button
return
Return key

Use the variable keyboard-translate-table only if you are on a
dumb tty, as it cannot handle input that cannot be represented as ASCII.
The value of this variable is a string used as a translate table for
keyboard input or nil.  Each character is looked up in this
string and the contents used instead.  If the string is of length
n, character codes N and up are untranslated.  If you are
running Emacs under X, you should do the translations with the
xmodmap program instead.


2.1.1 Representing Keystrokes
-----------------------------

  XEmacs represents keystrokes as lists. Each list consists of
an arbitrary combination of modifiers followed by a single keysym at the
end of the list.  If the keysym corresponds to an ASCII character, you
can use its character code.  (A keystroke may also be represented by an
event object, as returned by the read-key-sequence function;
non-programmers need not worry about this.)

The following table gives some examples of how to list representations
for keystrokes.  Each list consists of sets of modifiers followed by
keysyms:

(control a)
Pressing <CTRL> and a simultaneously.
(control ?a)
Another way of writing the keystroke C-a.
(control 65)
Yet another way of writing the keystroke C-a.
(break)
Pressing the <BREAK> key.
(control meta button2up)
Release the middle mouse button, while pressing <CTRL> and
<META>. 
  Note: As you define keystrokes, you can use the shift key only
as a modifier with characters that do not have a second keysym on the
same key, such as backspace and tab.  It is an error to
define a keystroke using the <shift> modifier with keysyms such as
a and =.  The correct forms are A and +.

2.1.2 Representing Key Sequences
--------------------------------

  A complete key sequence is a sequence of keystrokes that Emacs
understands as a unit.  Key sequences are significant because you can
bind them to commands.  Note that not all sequences of keystrokes are
possible key sequences.  In particular, the initial keystrokes in a key
sequence must make up a prefix key sequence.

  Emacs represents a key sequence as a vector of keystrokes.  Thus, the
schematic representation of a complete key sequence is as follows:

  [(modifier .. modifier keysym) ... (modifier .. modifier keysym)]

  Here are some examples of complete key sequences:

[(control c) (control a)]
Typing C-c followed by C-a
[(control c) (control 65)]
Typing C-c followed by C-a. (Using the ASCII code
for the character `a')
[(control c) (break)]
Typing C-c followed by the break character.


  A prefix key sequence is the beginning of a series of longer
sequences that are valid key sequences; adding any single keystroke to
the end of a prefix results in a valid key sequence.  For example,
control-x is standardly defined as a prefix.  Thus there is a
two-character key sequence starting with C-x for each valid
keystroke, giving numerous possibilities.  Here are some samples:

* [(control x) (c)]
* [(control x) (control c)]

  Adding one character to a prefix key does not have to form a complete
key.  It could make another, longer prefix.  For example, [(control
x) (\4)] is itself a prefix that leads to any number of different
three-character keys, including [(control x) (\4) (f)],
[(control x) (\4) (b)] and so on.  It would be possible to define
one of those three-character sequences as a prefix, creating a series of
four-character keys, but we did not define any of them this way.

  By contrast, the two-character sequence [(control f) (control
k)] is not a key, because the (control f) is a complete key
sequence in itself.  You cannot give [(control f (control k)] an
independent meaning as a command while (control f) is a complete
sequence, because Emacs would understand <C-f C-k> as two
commands.

 The predefined prefix key sequences in Emacs are (control c),
(control x), (control h), [(control x) (\4)], and
escape.  You can customize Emacs and could make new prefix keys or
eliminate the default key sequences.  See Key Bindings.  For example,
if you redefine (control f) as a prefix, [(control f)
(control k)] automatically becomes a valid key sequence (complete,
unless you define it as a prefix as well).  Conversely, if you remove
the prefix definition of [(control x) (\4)], [(control x)
(\4) (f)] (or [(control x) (\4) anything]) is no longer a
valid key sequence.

Note that the above paragraphs uses \4 instead of simply 4, because \4
is the symbol whose name is "4", and plain 4 is the integer 4, which
would have been interpreted as the ASCII value.  Another way of
representing the symbol whose name is "4" is to write ?4, which would be
interpreted as the number 52, which is the ASCII code for the character
"4".  We could therefore actually have written 52 directly, but that is
far less clear.

2.1.3 String Key Sequences
--------------------------
For backward compatibility, you may also represent a key sequence using
strings.  For example, we have the following equivalent representations:

"\C-c\C-c"
[(control c) (control c)]
"\e\C-c"
[(meta control c)]


2.1.4 Assignment of the <META> Key
----------------------------------
 
  Not all terminals have the complete set of modifiers.  
Terminals that have a <Meta> key allow you to type Meta characters
by just holding that key down.  To type Meta-a, hold down
<META> and press a.  On those terminals, the <META> key
works like the <SHIFT> key.  Such a key is not always labeled
<META>, however, as this function is often a special option for a
key with some other primary purpose.

  If there is no <META> key, you can still type Meta characters
using two-character sequences starting with <ESC>.  To enter
M-a, you could type <ESC> a.  To enter C-M-a, you
would type ESC C-a.  <ESC> is allowed on terminals with
Meta keys, too, in case you have formed a habit of using it.

If you are running under X and do not have a <META> key, it 
is possible to reconfigure some other key to be a <META> 
key.  See Super and Hyper Keys. 

  Emacs believes the terminal has a <META> key if the variable
meta-flag is non-nil.  Normally this is set automatically
according to the termcap entry for your terminal type.  However, sometimes
the termcap entry is wrong, and then it is useful to set this variable
yourself.  See Variables, for how to do this.

Note: If you are running under the X window system, the setting of
the meta-flag variable is irrelevant. 

2.1.5 Assignment of the <SUPER> and <HYPER> Keys
------------------------------------------------

  Most keyboards do not, by default, have <SUPER> or <HYPER>
modifier keys.  Under X, you can simulate the <SUPER> or
<HYPER> key if you want to bind keys to sequences using super
and hyper.  You can use the xmodmap program to do this.

  For example, to turn your <CAPS-LOCK> key into a <SUPER> key,
do the following:

  Create a file called ~/.xmodmap.  In this file, place the lines

        remove Lock = Caps_Lock
        keysym Caps_Lock = Super_L
        add Mod2 = Super_L

The first line says that the key that is currently called Caps_Lock
should no longer behave as a "lock" key.  The second line says that
this should now be called Super_L instead.  The third line says that 
the key called Super_L should be a modifier key, which produces the
Mod2 modifier.

To create a <META> or <HYPER> key instead of a <SUPER> key,
replace the word Super above with Meta or Hyper.

Just after you start up X, execute the command xmodmap /.xmodmap.
You can add this command to the appropriate initialization file to have
the command executed automatically.

If you have problems, see the documentation for the xmodmap
program.  The X keyboard model is quite complicated, and explaining
it is beyond the scope of this manual.  However, we reprint the 
following description from the X Protocol document for your convenience:


 A list of keysyms is associated with each keycode. If that list
(ignoring trailing NoSymbol entries) is a single keysym `K',
then the list is treated as if it were the list 
``K NoSymbol K NoSymbol''. If the list (ignoring trailing 
NoSymbol entries) is a pair of keysyms `K1 K2', then the 
list is treated as if it were the list ``K1 K2 K1 K2''. If the 
list (ignoring trailing NoSymbol entries) is a triple of keysyms 
`K1 K2 K3', then the list is treated as if it were the list 
``K1 K2 K3 NoSymbol''.

 The first four elements of the list are split into two groups of 
keysyms. Group 1 contains the first and second keysyms; Group 2 contains
third and fourth keysyms. Within each group, if the second element of
the group is NoSymbol, then the group should be treated as if the second
element were the same as the first element, except when the first
element is an alphabetic keysym `K' for which both lowercase and 
uppercase forms are defined. In that case, the group should be treated 
as if the first element were the lowercase form of `K' and the second 
element were the uppercase form of `K'.

 The standard rules for obtaining a keysym from a KeyPress event make use of 
only the Group 1 and Group 2 keysyms; no interpretation of other keysyms in 
the list is given here. (That is, the last four keysyms are unused.)

 Which group to use is determined by modifier state. Switching between
groups is controlled by the keysym named Mode_switch. Attach that
keysym to some keycode and attach that keycode to any one of the
modifiers Mod1 through Mod5. This modifier is called the group
modifier. For any keycode, Group 1 is used when the group modifier is
off, and Group 2 is used when the group modifier is on.

 Within a group, which keysym to use is also determined by modifier
state. The first keysym is used when the Shift and Lock 
modifiers are off. The second keysym is used when the Shift 
modifier is on, or when the Lock modifier is on and the second 
keysym is uppercase alphabetic, or when the Lock modifier is on 
and is interpreted as ShiftLock. Otherwise, when the Lock 
modifier is on and is interpreted as CapsLock, the state of the 
Shift modifier is applied first to select a keysym, 
but if that keysym is lower-case alphabetic, then the corresponding 
upper-case keysym is used instead.

 In addition to the above information on keysyms, we also provide the 
following description of modifier mapping from the InterClient 
Communications Conventions Manual:


 X11 supports 8 modifier bits, of which 3 are pre-assigned to 
Shift, Lock, and Control. Each modifier bit is 
controlled by the state of a set of keys, and these sets are specified 
in a table accessed by GetModifierMapping() and 
SetModifierMapping().

 A client needing to use one of the pre-assigned modifiers should assume
that the modifier table has been set up correctly to control these
modifiers. The Lock modifier should be interpreted as Caps
Lock or Shift Lock according to whether the keycodes in its
controlling set include XK_Caps_Lock or XK_Shift_Lock.

 Clients should determine the meaning of a modifier bit from the keysyms 
being used to control it.

A client needing to use an extra modifier, for example Meta, should:

1. Scan the existing modifier mappings.

1. If it finds a modifier that contains a keycode whose set of keysyms 
includes XK_Meta_L or XK_Meta_R, it should use that 
modifier bit.

2. If there is no existing modifier controlled by XK_Meta_L or 
XK_Meta_R, it should select an unused modifier bit (one with 
an empty controlling set) and:

2. If there is a keycode with XL_Meta_L in its set of keysyms, 
add that keycode to the set for the chosen modifier, and then:

1. If there is a keycode with XL_Meta_R in its set of keysyms, 
add that keycode to the set for the chosen modifier, and then:

2. If the controlling set is still empty, interact with the user to 
select one or more keys to be Meta.


3. If there are no unused modifier bits, ask the user to take corrective action.

 This means that the Mod1 modifier does not necessarily mean 
Meta, although some applications (such as twm and emacs 18) 
assume that. Any of the five unassigned modifier bits could mean 
Meta; what matters is that a modifier bit is generated by a 
keycode which is bound to the keysym Meta_L or Meta_R.

 Therefore, if you want to make a <META> key, the right way 
is to make the keycode in question generate both a Meta keysym 
and some previously-unassigned modifier bit.

2.2 Representation of Characters
================================

This section briefly discusses how characters are represented in Emacs
buffers.  See Key Sequences, for information on representing key
sequences to create key bindings. 

  ASCII graphic characters in Emacs buffers are displayed with their
graphics.  <LFD> is the same as a newline character; it is displayed
by starting a new line.  <TAB> is displayed by moving to the next
tab stop column (usually every 8 spaces).  Other control characters are
displayed as a caret (`^') followed by the non-control version of
the character; thus, C-a is displayed as `^A'.  Non-ASCII
characters 128 and up are displayed with octal escape sequences; thus,
character code 243 (octal), also called M-# when used as an input
character, is displayed as `\243'.

The variable ctl-arrow may be used to alter this behavior.
See Display Vars.

2.3 Keys and Commands
=====================

  This manual is full of passages that tell you what particular keys do.
But Emacs does not assign meanings to keys directly.  Instead, Emacs
assigns meanings to functions, and then gives keys their meanings
by binding them to functions.

 A function is a Lisp object that can be executed as a program.  Usually
it is a Lisp symbol that has been given a function definition; every
symbol has a name, usually made of a few English words separated by
dashes, such as next-line or forward-word.  It also has a
definition, which is a Lisp program.  Only some functions can be the
bindings of keys; these are functions whose definitions use
interactive to specify how to call them interactively.  Such
functions are called commands, and their names are command
names.  More information on this subject will appear in the XEmacs
Lisp Reference Manual.

  The bindings between keys and functions are recorded in various tables
called keymaps.  See Key Bindings, for more information on key
sequences you can bind commands to.  See Keymaps, for information on
creating keymaps.

  When we say  "C-n moves down vertically one line" we are
glossing over a distinction that is irrelevant in ordinary use but is
vital in understanding how to customize Emacs.  The function
next-line is programmed to move down vertically.  C-n
has this effect because it is bound to that function.  If you rebind
C-n to the function forward-word then C-n will move
forward by words instead.  Rebinding keys is a common method of
customization.

   The rest of this manual usually ignores this subtlety to keep
things simple.  To give the customizer the information needed, we often
state the name of the command that really does the work in parentheses
after mentioning the key that runs it.  For example, we will say that
"The command C-n (next-line) moves point vertically
down," meaning that next-line is a command that moves vertically
down and C-n is a key that is standardly bound to it.

  While we are on the subject of information for customization only,
it's a good time to tell you about variables.  Often the
description of a command will say, "To change this, set the variable
mumble-foo."  A variable is a name used to remember a value.
Most of the variables documented in this manual exist just to facilitate
customization: some command or other part of Emacs uses the variable
and behaves differently depending on its setting.  Until you are interested in
customizing, you can ignore the information about variables.  When you
are ready to be interested, read the basic information on variables, and 
then the information on individual variables will make sense.
See Variables.

2.4 XEmacs Pull-down Menus
==========================

If you are running XEmacs under X, a menu bar on top of the
Emacs frame provides access to pull-down menus of file, edit, and
help-related commands. The menus provide convenient shortcuts and an
easy interface for novice users.  They do not provide additions to the
functionality available via key commands; you can still invoke commands
from the keyboard as in previous versions of Emacs.
        
File
Perform file and buffer-related operations, such as opening and closing
files, saving and printing buffers, as well as exiting Emacs.

Edit
Perform standard editing operations, such as 
cutting, copying, pasting, and killing selected text.


Apps
Access to sub-applications implemented within XEmacs, such as the mail
reader, the World Wide Web browser, the spell-checker, and the calendar
program.

Options
Control various options regarding the way XEmacs works, such as controlling
which elements of the frame are visible, selecting the fonts to be used for
text, specifying whether searches are case-sensitive, etc.

Buffers
Present a menu of buffers for selection as well as the option to display
a buffer list.

Tools
Perform various actions designed to automate software development and
similar technical work, such as searching through many files, compiling
a program, and comparing or merging two or three files.

Help
Access to Emacs Info.

There are two ways of selecting an item from a pull-down menu:

* Select an item in the menu bar by moving the cursor over it and click the
left mouse-button.  Then move the cursor over the menu item you want to choose
and click left again.
* Select an item in the menu bar by moving the cursor over it and click and
hold the left mouse-button.  With the mouse-button depressed, move the
cursor over the menu item you want, then release it to make your selection. 

If a command in the pull-down menu is not applicable in a given
situation, the command is disabled and its name appears faded.  You
cannot invoke items that are faded.  For example, many commands on the
Edit menu appear faded until you select text on which they are to
operate; after you select a block of text, edit commands are enabled.
See Mouse Selection, for information on using the mouse to select
text.  See Using X Selections, for related information.

There are also M-x equivalents for each menu item.  To find the
equivalent for any left-button menu item, do the following:

1. Type C-h k to get the Describe Key prompt. 
2. Select the menu item and click. 

Emacs displays the function associated with the menu item in a separate
window, usually together with some documentation. 

* File Menu::           Items on the File menu.
* Edit Menu::           Items on the Edit menu.
* Apps Menu::		Items on the Apps menu.
* Options Menu::        Items on the Options menu. 
* Buffers Menu::        Information about the Buffers menu.
* Tools Menu::		Items on the Tools menu.
* Help Menu::           Items on the Help menu. 
* Menu Customization::  Adding and removing menu items and related
                        operations.

2.4.1 The File Menu
-------------------


The File menu bar item contains the items New Frame, Open
File..., Save Buffer, Save Buffer As..., Revert Buffer,
Print Buffer, Delete Frame, Kill Buffer and Exit Emacs
on the pull-down menu.  If you select a menu item, Emacs executes the
equivalent command.


Open File, New Frame...
Prompts you for a filename and loads that file into a new buffer in a
new Emacs frame, that is, a new X window running under the same Emacs
process.  You can remove the frame using the Delete Frame menu
item.  When you remove the last frame, you exit Emacs and are prompted
for confirmation. 

Open File...
Prompts you for a filename and loads that file into a new buffer. 
Open File... is equivalent to the Emacs command find-file (C-x
C-f). 

Insert File...
Prompts you for a filename and inserts the contents of that file into
the current buffer.  The file associated with the current buffer is
not changed by this command.  This is equivalent to the Emacs command
insert-file (C-x i). 

Save Buffer
Writes and saves the current Emacs buffer as the latest
version of the current visited file.  Save Buffer is equivalent to the
Emacs command save-buffer (C-x C-s).

Save Buffer As...
Writes and saves the current Emacs buffer to the filename you specify.
Save Buffer As... is equivalent to the Emacs command
write-file (C-x C-w).

Revert Buffer
Restores the last saved version of the file to the current buffer.  When
you edit a buffer containing a text file, you must save the buffer
before your changes become effective.  Use Revert Buffer if you do
not want to keep the changes you have made in the buffer.  Revert
Buffer is equivalent to the Emacs command revert-file (M-x
revert-buffer).

Kill Buffer
Kills the current buffer, prompting you first if there are unsaved
changes.  This is roughly equivalent to the Emacs command 
kill-buffer (C-x k), except that kill-buffer 
prompts for the name of a buffer to kill. 

Print Buffer
Prints a hardcopy of the current buffer.  Equivalent
to the Emacs command print-buffer (M-x print-buffer).

New Frame
Creates a new Emacs frame displaying the *scratch* buffer.  This
is like the Open File, New Frame... menu item, except that it does
not prompt for or load a file.

Delete Frame
Allows you to close all but one of the frames created by New Frame.
If you created several Emacs frames belonging to the same Emacs
process, you can close all but one of them.  When you attempt to close the
last frame, Emacs informs you that you are attempting to delete the
last frame.  You have to choose Exit Emacs for that.

Split Frame
Divides the current window on the current frame into two equal-sized
windows, both displaying the same buffer.  Equivalent to the Emacs
command split-window-vertically (C-x 2).

Un-split (Keep This)
If the frame is divided into multiple windows, this removes all windows
other than the selected one.  Equivalent to the Emacs command
delete-other-windows (C-x 1).

Un-split (Keep Others)
If the frame is divided into multiple windows, this removes the
selected window from the frame, giving the space back to one of the
other windows.  Equivalent to the Emacs command delete-window
(C-x 0).

Exit Emacs
Shuts down (kills) the Emacs process.  Equivalent to the Emacs command
save-buffers-kill-emacs (C-x C-c).  Before killing the
Emacs process, the system asks which unsaved buffers to save by going through
the list of all buffers in that Emacs process.

2.4.2 The Edit Menu
-------------------

The Edit pull-down menu contains the Undo, Cut, Copy,
Paste, and Clear menu items.  When you select a menu item, Emacs
executes the equivalent command.  Most commands on the Edit menu
work on a block of text, the X selection.  They appear faded until you
select a block of text (activate a region) with the mouse.  See Using X Selections, see Killing, and see Yanking for more
information.


Undo
Undoes the previous command.  Undo is equivalent to
the Emacs command undo (C-x u).

Cut
Removes the selected text block from the current buffer, makes it the X
clipboard selection, and places it in the kill ring.  Before executing
this command, you have to select a region using Emacs region selection
commands or with the mouse. 

Copy
Makes a selected text block the X clipboard selection, and places it in
the kill ring.  You can select text using one of the Emacs region
selection commands or by selecting a text region with the mouse.

Paste
Inserts the current value of the X clipboard selection in the current
buffer.  Note that this is not necessarily the same as the Emacs
yank command, because the Emacs kill ring and the X clipboard
selection are not the same thing.  You can paste in text you
have placed in the clipboard using Copy or Cut.  You can also
use Paste to insert text that was pasted into the clipboard from other
applications.

Clear
Removes the selected text block from the current buffer but does not
place it in the kill ring or the X clipboard selection. 

Start Macro Recording
After selecting this, Emacs will remember every keystroke you type until
End Macro Recording is selected.  This is the same as the Emacs 
command start-kbd-macro (C-x ().

End Macro Recording
Selecting this tells emacs to stop remembering your keystrokes.  This is
the same as the Emacs command end-kbd-macro (C-x )).

Execute Last Macro
Selecting this item will cause emacs to re-interpret all of the
keystrokes which were saved between selections of the Start Macro
Recording and End Macro Recording menu items.  This is the same
as the Emacs command call-last-kbd-macro (C-x e).

2.4.3 The Apps Menu
-------------------

The Apps pull-down menu contains the Read Mail (VM)..., Read
Mail (MH)..., Send Mail..., Usenet News, Browse the Web,
Gopher, Spell-Check Buffer and Emulate VI menu items,
and the Calendar and Games sub-menus.  When you select a menu
item, Emacs executes the equivalent command.  For some of the menu
items, there are sub-menus which you will need to select.

2.4.4 The Options Menu
----------------------

The Options pull-down menu contains the Read Only, Case 
Sensitive Search, Overstrike, Auto Delete Selection, 
Teach Extended Commands, Syntax Highlighting, Paren 
Highlighting, Font, Size, Weight, Buffers Menu 
Length..., Buffers Sub-Menus and Save Options menu items. 
When you select a menu item, Emacs executes the equivalent command. 
For some of the menu items, there are sub-menus which you will need 
to select.

Read Only
Selecting this item will cause the buffer to visit the file in a 
read-only mode. Changes to the file will not be allowed. This is 
equivalent to the Emacs command toggle-read-only 
(C-x C-q).

Case Sensitive Search
Selecting this item will cause searches to be case-sensitive. If 
its not selected then searches will ignore case. This option is 
local to the buffer.

Overstrike
After selecting this item, when you type letters they will replace 
existing text on a one-to-one basis, rather than pushing it to the 
right. At the end of a line, such characters extend the line. Before 
a tab, such characters insert until the tab is filled in. This is the 
same as Emacs command quoted-insert (C-q).

Auto Delete Selection
Selecting this item will cause automatic deletion of the selected 
region. The typed text will replace the selection if the selection 
is active (i.e. if its highlighted). If the option is not selected 
then the typed text is just inserted at the point.

Teach Extended Commands
After you  select this item, any time you execute a command with 
M-xwhich has a shorter keybinding, you will be shown the 
alternate binding before the command executes.

Syntax Highlighting
You can customize your init file to include the font-lock mode so that
when you select this item, the comments will be displayed in one face,
strings in another, reserved words in another, and so on. See Init File.  When Fonts is selected, different parts of the program will
appear in different Fonts. When Colors is selected, then the program
will be displayed in different colors. Selecting None causes the
program to appear in just one Font and Color. Selecting Less resets
the Fonts and Colors to a fast, minimal set of decorations. Selecting
More resets the Fonts and Colors to a larger set of decorations. For
example, if Less is selected (which is the default setting) then you
might have all comments in green color.  Whereas, if More is
selected then a function name in the comments themselves might appear in
a different Color or Font.

Paren Highlighting
After selecting Blink from this item, if you place the cursor 
on a parenthesis, the matching parenthesis will blink. If you select 
Highlight and place the cursor on a parenthesis, the whole 
expression of the parenthesis under the cursor will be highlighted. 
Selecting None will turn off the options (regarding Paren 
Highlighting) which you had selected earlier.

Font
You can select any Font for your program by choosing from one of the 
available Fonts.

Size
You can select any size ranging from 2 to 24 by selecting the 
appropriate option.

Weight
You can choose either Bold or Medium for the weight.

Buffers Menu Length...
Prompts you for the number of buffers to display. Then it will display 
that number of most recently selected buffers.

Buffers Sub-Menus
After selection of this item the Buffers menu will contain several 
commands, as submenus of each buffer line. If this item is unselected, 
then there are no submenus for each buffer line, the only command 
available will be selecting that buffer.

Save Options
Selecting this item will save the current settings of your Options 
menu to your init file.  See Init File.

2.4.5 The Buffers Menu
----------------------
The Buffers menu provides a selection of up to ten buffers and the
item List All Buffers, which provides a Buffer List. See List Buffers, for more information.  

2.4.6 The Tools Menu
--------------------

The Tools pull-down menu contains the Grep..., Compile...,
Shell Command..., Shell Command on Region..., Debug(GDB)...
and Debug(DBX)... menu items, and the Compare, Merge,
Apply Patch and Tags sub-menus.  When you select a menu item,
Emacs executes the equivalent command.  For some of the menu items,
there are sub-menus which you will need to select.

2.4.7 The Help Menu
-------------------

The Help Menu gives you access to Emacs Info and provides a menu
equivalent for each of the choices you have when using C-h. 
See Help, for more information. 

The Help menu also gives access to UNIX online manual pages via the
UNIX Manual Page option.  

2.4.8 Customizing XEmacs Menus
------------------------------

You can customize any of the pull-down menus by adding or removing menu
items and disabling or enabling existing menu items.
 
The following functions are available: 
add-menu: (menu-path menu-name menu-items &optional before)
Add a menu to the menu bar or one of its submenus.
add-menu-item: (menu-path item-name function
enabled-p &optional before)
Add a menu item to a menu, creating the menu first if necessary.
delete-menu-item: (path)
Remove the menu item defined by path from the menu hierarchy.
disable-menu-item: (path)
Disable the specified menu item.
enable-menu-item: (path)
Enable the specified previously disabled menu item.
relabel-menu-item: (path new-name)
Change the string of the menu item specified by path to
new-name.


Use the function add-menu to add a new menu or submenu.
If a menu or submenu of the given name exists already, it is changed.

menu-path identifies the menu under which the new menu should be
inserted.  It is a list of strings; for example, ("File") names
the top-level File menu.  ("File" "Foo") names a hypothetical
submenu of File.  If menu-path is nil, the menu is
added to the menu bar itself.

menu-name is the string naming the menu to be added.  

menu-items is a list of menu item descriptions.  Each menu item
should be a vector of three elements:

* A string, which is the name of the menu item
* A symbol naming a command, or a form to evaluate
* t or nil to indicate whether the item is selectable

The optional argument before is the name of the menu before which
the new menu or submenu should be added.  If the menu is already
present, it is not moved.

The function add-menu-item adds a menu item to the specified
menu, creating the menu first if necessary.  If the named item already
exists, the menu remains unchanged.

menu-path identifies the menu into which the new menu item should
be inserted.  It is a list of strings; for example, ("File")
names the top-level File menu.  ("File" "Foo") names a
hypothetical submenu of File.

item-name is the string naming the menu item to add.

function is the command to invoke when this menu item is selected.
If it is a symbol, it is invoked with call-interactively, in the
same way that functions bound to keys are invoked.  If it is a list, the
list is simply evaluated.

enabled-p controls whether the item is selectable or not.
It should be t, nil, or a form to evaluate to decide.  
This form will be evaluated just before the menu is displayed, and 
the menu item will be selectable if that form returns non-nil.

For example, to make the rename-file command available from the
File menu, use the following code:

(add-menu-item '("File") "Rename File" 'rename-file t)

To add a submenu of file management commands using a File Management
item, use the following code: 

(add-menu-item '("File" "File Management") "Copy File" 'copy-file t)
(add-menu-item '("File" "File Management") "Delete File" 'delete-file t)
(add-menu-item '("File" "File Management") "Rename File" 'rename-file t)

The optional before argument is the name of a menu item before
which the new item should be added.  If the item is already present, it
is not moved.

To remove a specified menu item from the menu hierarchy, use
delete-menu-item.

path is a list of strings that identify the position of the menu
item in the menu hierarchy.  ("File" "Save") means the menu item
called Save under the top level File menu.  ("Menu" "Foo"
"Item") means the menu item called Item under the Foo submenu
of Menu.


To disable a menu item, use disable-menu-item.  The disabled
menu item is grayed and can no longer be selected.  To make the
item selectable again, use enable-menu-item.
disable-menu-item and enable-menu-item both have the
argument path.

To change the string of the specified menu item, use
relabel-menu-item. This function also takes the argument path.

new-name is the string to which the menu item will be changed.
