@c -*-texinfo-*-
@c This is part of the GNU Emacs Lisp Reference Manual.
-@c Copyright (C) 1990-1995, 1998-1999, 2001-2012 Free Software Foundation, Inc.
+@c Copyright (C) 1990-1995, 1998-1999, 2001-2014 Free Software
+@c Foundation, Inc.
@c See the file elisp.texi for copying conditions.
@node Command Loop
@chapter Command Loop
Lisp code, you must supply the file name string as an ordinary Lisp
function argument.
- If the command is a keyboard macro (i.e.@: a string or vector),
+ If the command is a keyboard macro (i.e., a string or vector),
Emacs executes it using @code{execute-kbd-macro} (@pxref{Keyboard
Macros}).
The special form @code{interactive} turns a Lisp function into a
command. The @code{interactive} form must be located at top-level in
-the function body (usually as the first form in the body), or in the
-@code{interactive-form} property of the function symbol. When the
-@code{interactive} form is located in the function body, it does
-nothing when actually executed. Its presence serves as a flag, which
-tells the Emacs command loop that the function can be called
-interactively. The argument of the @code{interactive} form controls
-the reading of arguments for an interactive call.
+the function body, usually as the first form in the body; this applies
+to both lambda expressions (@pxref{Lambda Expressions}) and
+@code{defun} forms (@pxref{Defining Functions}). This form does
+nothing during the actual execution of the function; its presence
+serves as a flag, telling the Emacs command loop that the function can
+be called interactively. The argument of the @code{interactive} form
+specifies how the arguments for an interactive call should be read.
+
+@cindex @code{interactive-form} property
+ Alternatively, an @code{interactive} form may be specified in a
+function symbol's @code{interactive-form} property. A non-@code{nil}
+value for this property takes precedence over any @code{interactive}
+form in the function body itself. This feature is seldom used.
+
+@cindex @code{interactive-only} property
+ Sometimes, a named command is only intended to be called
+interactively, never directly from Lisp. In that case, give it a
+non-@code{nil} @code{interactive-only} property. In that case, the
+byte compiler will print a warning message if the command is called
+from Lisp.
@menu
* Using Interactive:: General rules for @code{interactive}.
then the caller supplies the arguments and @var{arg-descriptor} has no
effect.
-@cindex @code{interactive-form}, function property
+@cindex @code{interactive-form}, symbol property
The @code{interactive} form must be located at top-level in the
function body, or in the function symbol's @code{interactive-form}
-property (@pxref{Symbol Plists}). It has its effect because the
+property (@pxref{Symbol Properties}). It has its effect because the
command loop looks for it before calling the function
(@pxref{Interactive Call}). Once the function is called, all its body
forms are executed; at this time, if the @code{interactive} form
the name of an existing buffer, which becomes the second and final
argument.
-@c Emacs 19 feature
The prompt string can use @samp{%} to include previous argument values
(starting with the first argument) in the prompt. This is done using
@code{format} (@pxref{Formatting Strings}). For example, here is how
signaled if the buffer is read-only.
@cindex @samp{@@} in @code{interactive}
-@c Emacs 19 feature
If @samp{@@} appears at the beginning of the string, and if the key
sequence used to invoke the command includes any mouse events, then
the window associated with the first of those events is selected
these characters in the input.) Prompt.
@item S
-An interned symbol whose name is read in the minibuffer. Any whitespace
-character terminates the input. (Use @kbd{C-q} to include whitespace in
-the string.) Other characters that normally terminate a symbol (e.g.,
-parentheses and brackets) do not do so here. Prompt.
+An interned symbol whose name is read in the minibuffer. Terminate
+the input with either @kbd{C-j} or @key{RET}. Other characters that
+normally terminate a symbol (e.g., whitespace, parentheses and
+brackets) do not do so here. Prompt.
@item U
A key sequence or @code{nil}. Can be used after a @samp{k} or
@end defvar
@defvar last-command-event
-@defvarx last-command-char
This variable is set to the last input event that was read by the
command loop as part of a command. The principal use of this variable
is in @code{self-insert-command}, which uses it to decide which
@noindent
The value is 5 because that is the @acronym{ASCII} code for @kbd{C-e}.
-
-The alias @code{last-command-char} is obsolete.
@end defvar
-@c Emacs 19 feature
@defvar last-event-frame
This variable records which frame the last input event was directed to.
Usually this is the frame that was selected when the event was
@end example
@defvar num-input-keys
-@c Emacs 19 feature
This variable's value is the number of key sequences processed so far in
this Emacs session. This includes key sequences read from the terminal
and key sequences read from keyboard macros being executed.
@code{read-char}, and @code{read-char-exclusive}.
@defun read-event &optional prompt inherit-input-method seconds
-This function reads and returns the next event of command input, waiting
-if necessary until an event is available. Events can come directly from
-the user or from a keyboard macro.
+This function reads and returns the next event of command input,
+waiting if necessary until an event is available.
+
+The returned event may come directly from the user, or from a keyboard
+macro. It is not decoded by the keyboard's input coding system
+(@pxref{Terminal I/O Encoding}).
If the optional argument @var{prompt} is non-@code{nil}, it should be a
string to display in the echo area as a prompt. Otherwise,
@defun read-char &optional prompt inherit-input-method seconds
This function reads and returns a character of command input. If the
-user generates an event which is not a character (i.e. a mouse click or
+user generates an event which is not a character (i.e., a mouse click or
function key event), @code{read-char} signals an error. The arguments
work as in @code{read-event}.
@code{keyboard-translate-table} (if applicable), before returning it
from @code{read-event}.
-@c Emacs 19 feature
@defvar extra-keyboard-modifiers
This variable lets Lisp programs ``press'' the modifier keys on the
keyboard. The value is a character. Only the modifiers of the
@cindex control characters, reading
@cindex nonprinting characters, reading
This function is like @code{read-char}, except that if the first
-character read is an octal digit (0-7), it reads any number of octal
+character read is an octal digit (0--7), it reads any number of octal
digits (but stopping if a non-octal digit is found), and returns the
character represented by that numeric character code. If the
character that terminates the sequence of octal digits is @key{RET},
most recently unread will be reread first.
Events read from this list are not normally added to the current
-command's key sequence (as returned by e.g. @code{this-command-keys}),
+command's key sequence (as returned by, e.g., @code{this-command-keys}),
as the events will already have been added once as they were read for
the first time. An element of the form @code{(@code{t} . @var{event})}
forces @var{event} to be added to the current command's key sequence.
individual events, which you can put in @code{unread-command-events}.
@end defun
-@defun input-pending-p
+@defun input-pending-p &optional check-timers
@cindex waiting for command key input
This function determines whether any command input is currently
available to be read. It returns immediately, with value @code{t} if
there is available input, @code{nil} otherwise. On rare occasions it
may return @code{t} when no input is available.
+
+If the optional argument @var{check-timers} is non-@code{nil}, then if
+no input is available, Emacs runs any timers which are ready.
+@xref{Timers}.
@end defun
@defvar last-input-event
-@defvarx last-input-char
This variable records the last terminal input event read, whether
as part of a command or explicitly by a Lisp program.
@result{} 49
@end group
@end example
-
-The alias @code{last-input-char} is obsolete.
@end defvar
@defmac while-no-input body@dots{}
@var{seconds} is rounded down.
The expression @code{(sit-for 0)} is equivalent to @code{(redisplay)},
-i.e. it requests a redisplay, without any delay, if there is no pending input.
+i.e., it requests a redisplay, without any delay, if there is no pending input.
@xref{Forcing Redisplay}.
If @var{nodisp} is non-@code{nil}, then @code{sit-for} does not
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