@c -*-texinfo-*-
@c This is part of the GNU Emacs Lisp Reference Manual.
-@c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1998, 1999, 2002, 2003,
-@c 2004, 2005 Free Software Foundation, Inc.
+@c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1998, 1999, 2001,
+@c 2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
@c See the file elisp.texi for copying conditions.
@setfilename ../info/os
@node System Interface, Antinews, Display, Top
* Processor Run Time:: Getting the run time used by Emacs.
* Time Calculations:: Adding, subtracting, comparing times, etc.
* Timers:: Setting a timer to call a function at a certain time.
-* Terminal Input:: Recording terminal input for debugging.
-* Terminal Output:: Recording terminal output for debugging.
+* Idle Timers:: Setting a timer to call a function when Emacs has
+ been idle for a certain length of time.
+* Terminal Input:: Accessing and recording terminal input.
+* Terminal Output:: Controlling and recording terminal output.
* Sound Output:: Playing sounds on the computer's speaker.
* X11 Keysyms:: Operating on key symbols for X Windows
* Batch Mode:: Running Emacs without terminal interaction.
@node Startup Summary
@subsection Summary: Sequence of Actions at Startup
-@cindex initialization
+@cindex initialization of Emacs
@cindex startup of Emacs
@cindex @file{startup.el}
@item
It displays the initial echo area message, unless you have suppressed
-that with @code{inhibit-startup-echo-area-message} or @samp{-Q}.
+that with @code{inhibit-startup-echo-area-message}.
@item
It processes the action arguments from the command line.
@item
It displays copyleft, nonwarranty, and basic use information, provided
the value of @code{inhibit-startup-message} is @code{nil}, you didn't
-specify @samp{--no-splash} or @samp{-Q}, and the buffer is still empty.
+specify @samp{--no-splash} or @samp{-Q}.
@end enumerate
@defopt inhibit-startup-message
When you start Emacs, it normally attempts to load your @dfn{init
file}, a file in your home directory. Its normal name is
-@file{.emacs}, but you can alternatively call it @file{.emacs.el}.
-You can also store it inside a subdirectory @file{.emacs.d}.
-Whichever place you use, you can also compile the file (@pxref{Byte
-Compilation}); then the actual file loaded will be @file{.emacs.elc}.
+@file{.emacs}, but you can also call it @file{.emacs.el}.
+Alternatively, you can use a file named @file{init.el} in a
+subdirectory @file{.emacs.d}. Whichever place you use, you can also
+compile the file (@pxref{Byte Compilation}); then the actual file
+loaded will be @file{.emacs.elc} or @file{init.elc}.
The command-line switches @samp{-q}, @samp{-Q}, and @samp{-u}
control whether and where to find the init file; @samp{-q} (and the
@end defvar
@defvar emacs-startup-hook
-@tindex emacs-startup-hook
This normal hook is run, once, just after handling the command line
arguments, just before @code{term-setup-hook}.
@end defvar
@defvar user-init-file
-@tindex user-init-file
This variable holds the absolute file name of the user's init file. If the
actual init file loaded is a compiled file, such as @file{.emacs.elc},
the value refers to the corresponding source file.
in the normal manner, by searching the @code{load-path} directories, and
trying the @samp{.elc} and @samp{.el} suffixes.
- The usual function of a terminal-specific library is to enable special
-keys to send sequences that Emacs can recognize. It may also need to
-set or add to @code{function-key-map} if the Termcap entry does not
-specify all the terminal's function keys. @xref{Terminal Input}.
-
@cindex Termcap
- When the name of 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 @samp{aaa-48} and @samp{aaa-30-rv} both use
-the @file{term/aaa} library. If necessary, the library can evaluate
-@code{(getenv "TERM")} to find the full name of the terminal
-type.@refill
+ The usual function of a terminal-specific library is to enable
+special keys to send sequences that Emacs can recognize. It may also
+need to set or add to @code{function-key-map} if the Termcap or
+Terminfo entry does not specify all the terminal's function keys.
+@xref{Terminal Input}.
+
+ When the name of the terminal type contains a hyphen, and no library
+is found whose name is identical to the terminal's name, Emacs strips
+from the terminal's name the last hyphen and everything that follows
+it, and tries again. This process is repeated until Emacs finds a
+matching library or until there are no more hyphens in the name (the
+latter means the terminal doesn't have any library specific to it).
+Thus, for example, if there are no @samp{aaa-48} and @samp{aaa-30}
+libraries, Emacs will try the same library @file{term/aaa.el} for
+terminal types @samp{aaa-48} and @samp{aaa-30-rv}. If necessary, the
+library can evaluate @code{(getenv "TERM")} to find the full name of
+the terminal type.@refill
Your init file can prevent the loading of the
terminal-specific library by setting the variable
arguments is in @code{command-line-args}.)
The command-line arguments are parsed by the @code{command-line-1}
-function in the @file{startup.el} file. See also @ref{Command
-Arguments, , Command Line Arguments, emacs, The GNU Emacs Manual}.
+function in the @file{startup.el} file. See also @ref{Emacs
+Invocation, , Command Line Arguments for Emacs Invocation, emacs, The
+GNU Emacs Manual}.
@end defvar
@defvar command-line-args
may not have a parent that can resume it again, and in any case you can
give input to some other job such as a shell merely by moving to a
different window. Therefore, suspending is not allowed when Emacs is using
-a window system (X or MS Windows).
+a window system (X, MS Windows, or Mac).
@defun suspend-emacs &optional string
This function stops Emacs and returns control to the superior process.
@code{string-match}.
@end defvar
+@cindex system type and name
@defvar system-type
The value of this variable is a symbol indicating the type of operating
system Emacs is operating on. Here is a table of the possible values:
@end defvar
@defun parse-colon-path path
-@tindex parse-colon-path
This function takes a search path string such as would be the value of
the @code{PATH} environment variable, and splits it at the separators,
returning a list of directory names. @code{nil} in this list stands for
@node User Identification
@section User Identification
+@cindex user identification
@defvar init-file-user
This variable says which user's init files should be used by
@var{offset} is an integer giving the number of seconds ahead of UTC
(east of Greenwich). A negative value means west of Greenwich. The
second element, @var{name}, is a string giving the name of the time
-zone. Both elements change when daylight savings time begins or ends;
+zone. Both elements change when daylight saving time begins or ends;
if the user has specified a time zone that does not use a seasonal time
adjustment, then the value is constant through time.
The day of week, as an integer between 0 and 6, where 0 stands for
Sunday.
@item dst
-@code{t} if daylight savings time is effect, otherwise @code{nil}.
+@code{t} if daylight saving time is effect, otherwise @code{nil}.
@item zone
An integer indicating the time zone, as the number of seconds east of
Greenwich.
yourself before you call @code{encode-time}.
The optional argument @var{zone} defaults to the current time zone and
-its daylight savings time rules. If specified, it can be either a list
+its daylight saving time rules. If specified, it can be either a list
(as you would get from @code{current-time-zone}), a string as in the
@code{TZ} environment variable, @code{t} for Universal Time, or an
integer (as you would get from @code{decode-time}). The specified
-zone is used without any further alteration for daylight savings time.
+zone is used without any further alteration for daylight saving time.
If you pass more than seven arguments to @code{encode-time}, the first
six are used as @var{seconds} through @var{year}, the last argument is
@item %Y
This stands for the year with century.
@item %Z
-This stands for the time zone abbreviation.
+This stands for the time zone abbreviation (e.g., @samp{EST}).
+@item %z
+This stands for the time zone numerical offset (e.g., @samp{-0500}).
@end table
You can also specify the field width and type of padding for any of
Universal Time; @code{nil} means describe it using what Emacs believes
is the local time zone (see @code{current-time-zone}).
-This function uses the C library function @code{strftime} to do most of
-the work. In order to communicate with that function, it first encodes
-its argument using the coding system specified by
-@code{locale-coding-system} (@pxref{Locales}); after @code{strftime}
-returns the resulting string, @code{format-time-string} decodes the
-string using that same coding system.
+This function uses the C library function @code{strftime}
+(@pxref{Formatting Calendar Time,,, libc, The GNU C Library Reference
+Manual}) to do most of the work. In order to communicate with that
+function, it first encodes its argument using the coding system
+specified by @code{locale-coding-system} (@pxref{Locales}); after
+@code{strftime} returns the resulting string,
+@code{format-time-string} decodes the string using that same coding
+system.
@end defun
@defun seconds-to-time seconds
@node Processor Run Time
@section Processor Run time
+@cindex processor run time
@defun get-internal-run-time
This function returns the processor run time used by Emacs as a list
things in an inconsistent state. This is normally unproblematical
because most timer functions don't do a lot of work. Indeed, for a
timer to call a function that takes substantial time to run is likely
-to be annoying.
+to be annoying. If a timer function needs to allow quitting, it
+should use @code{with-local-quit} (@pxref{Quitting}). For example, if
+a timer function calls @code{accept-process-output} to receive output
+from an external process, that call should be wrapped inside
+@code{with-local-quit}, to ensure that @kbd{C-g} works if the external
+process hangs.
It is usually a bad idea for timer functions to alter buffer
contents. When they do, they usually should call @code{undo-boundary}
changes from user commands' changes and prevent a single undo entry
from growing to be quite large.
+ Timer functions should also avoid calling functions that cause Emacs
+to wait, such as @code{sit-for} (@pxref{Waiting}). This can lead to
+unpredictable effects, since other timers (or even the same timer) can
+run while waiting. If a timer function needs to perform an action
+after a certain time has elapsed, it can do this by scheduling a new
+timer.
+
If a timer function calls functions that can change the match data,
it should save and restore the match data. @xref{Saving Match Data}.
@deffn Command run-at-time time repeat function &rest args
This sets up a timer that calls the function @var{function} with
arguments @var{args} at time @var{time}. If @var{repeat} is a number
-(integer or floating point), the timer also runs every @var{repeat}
-seconds after that. If @var{repeat} is @code{nil}, the timer runs
-only once.
+(integer or floating point), the timer is scheduled to run again every
+@var{repeat} seconds after @var{time}. If @var{repeat} is @code{nil},
+the timer runs only once.
@var{time} may specify an absolute or a relative time.
-Absolute times may be specified in a wide variety of formats; this
-function tries to accept all the commonly used date formats. The most
-convenient formats are strings. Valid such formats include these two,
-
-@example
-@var{year}-@var{month}-@var{day} @var{hour}:@var{min}:@var{sec} @var{timezone}
-
-@var{hour}:@var{min}:@var{sec} @var{timezone} @var{month}/@var{day}/@var{year}
-@end example
-
-@noindent
-where in both examples all fields are numbers; the format that
-@code{current-time-string} returns is also allowed, and many others
-as well.
+Absolute times may be specified using a string with a limited variety
+of formats, and are taken to be times @emph{today}, even if already in
+the past. The recognized forms are @samp{@var{xxxx}},
+@samp{@var{x}:@var{xx}}, or @samp{@var{xx}:@var{xx}} (military time),
+and @samp{@var{xx}am}, @samp{@var{xx}AM}, @samp{@var{xx}pm},
+@samp{@var{xx}PM}, @samp{@var{xx}:@var{xx}am},
+@samp{@var{xx}:@var{xx}AM}, @samp{@var{xx}:@var{xx}pm}, or
+@samp{@var{xx}:@var{xx}PM}. A period can be used instead of a colon
+to separate the hour and minute parts.
To specify a relative time as a string, use numbers followed by units.
For example:
days, and a year to be exactly 365.25 days.
Not all convenient formats are strings. If @var{time} is a number
-(integer or floating point), that specifies a relative time measured
-in seconds.
+(integer or floating point), that specifies a relative time measured in
+seconds. The result of @code{encode-time} can also be used to specify
+an absolute value for @var{time}.
In most cases, @var{repeat} has no effect on when @emph{first} call
takes place---@var{time} alone specifies that. There is one exception:
@code{cancel-timer} (see below).
@end deffn
+ A repeating timer nominally ought to run every @var{repeat} seconds,
+but remember that any invocation of a timer can be late. Lateness of
+one repetition has no effect on the scheduled time of the next
+repetition. For instance, if Emacs is busy computing for long enough
+to cover three scheduled repetitions of the timer, and then starts to
+wait, it will immediately call the timer function three times in
+immediate succession (presuming no other timers trigger before or
+between them). If you want a timer to run again no less than @var{n}
+seconds after the last invocation, don't use the @var{repeat} argument.
+Instead, the timer function should explicitly reschedule the timer.
+
+@defvar timer-max-repeats
+This variable's value specifies the maximum number of times to repeat
+calling a timer function in a row, when many previously scheduled
+calls were unavoidably delayed.
+@end defvar
+
@defmac with-timeout (seconds timeout-forms@dots{}) body@dots{}
Execute @var{body}, but give up after @var{seconds} seconds. If
@var{body} finishes before the time is up, @code{with-timeout} returns
a timer to avoid waiting too long for an answer. @xref{Yes-or-No
Queries}.
+@defun cancel-timer timer
+This cancels the requested action for @var{timer}, which should be a
+timer---usually, one previously returned by @code{run-at-time} or
+@code{run-with-idle-timer}. This cancels the effect of that call to
+one of these functions; the arrival of the specified time will not
+cause anything special to happen.
+@end defun
+
+@node Idle Timers
+@section Idle Timers
+
+ Here is how to set up a timer that runs when Emacs is idle for a
+certain length of time. Aside from how to set them up, idle timers
+work just like ordinary timers.
+
@deffn Command run-with-idle-timer secs repeat function &rest args
Set up a timer which runs when Emacs has been idle for @var{secs}
seconds. The value of @var{secs} may be an integer or a floating point
-number.
+number; a value of the type returned by @code{current-idle-time}
+is also allowed.
If @var{repeat} is @code{nil}, the timer runs just once, the first time
Emacs remains idle for a long enough time. More often @var{repeat} is
remains idle for @var{secs} seconds.
The function @code{run-with-idle-timer} returns a timer value which you
-can use in calling @code{cancel-timer} (see below).
+can use in calling @code{cancel-timer} (@pxref{Timers}).
@end deffn
@cindex idleness
input. Then it becomes idle again, and all the idle timers that are
set up to repeat will subsequently run another time, one by one.
-@defun cancel-timer timer
-Cancel the requested action for @var{timer}, which should be a value
-previously returned by @code{run-at-time} or @code{run-with-idle-timer}.
-This cancels the effect of that call to one of these functions; the
-arrival of the specified time will not cause anything special to happen.
+@c Emacs 19 feature
+@defun current-idle-time
+If Emacs is idle, this function returns the length of time Emacs has
+been idle, as a list of three integers: @code{(@var{high} @var{low}
+@var{microsec})}. The integers @var{high} and @var{low} combine to
+give the number of seconds of idleness, which is
+@ifnottex
+@var{high} * 2**16 + @var{low}.
+@end ifnottex
+@tex
+$high*2^{16}+low$.
+@end tex
+
+The third element, @var{microsec}, gives the microseconds since the
+start of the current second (or 0 for systems that return time with
+the resolution of only one second).
+
+When Emacs is not idle, @code{current-idle-time} returns @code{nil}.
+This is a convenient way to test whether Emacs is idle.
+
+The main use of this function is when an idle timer function wants to
+``take a break'' for a while. It can set up another idle timer to
+call the same function again, after a few seconds more idleness.
+Here's an example:
+
+@smallexample
+(defvar resume-timer nil
+ "Timer that `timer-function' used to reschedule itself, or nil.")
+
+(defun timer-function ()
+ ;; @r{If the user types a command while @code{resume-timer}}
+ ;; @r{is active, the next time this function is called from}
+ ;; @r{its main idle timer, deactivate @code{resume-timer}.}
+ (when resume-timer
+ (cancel-timer resume-timer))
+ ...@var{do the work for a while}...
+ (when @var{taking-a-break}
+ (setq resume-timer
+ (run-with-idle-timer
+ ;; Compute an idle time @var{break-length}
+ ;; more than the current value.
+ (time-add (current-idle-time)
+ (seconds-to-time @var{break-length}))
+ nil
+ 'timer-function))))
+@end smallexample
@end defun
+ Some idle timer functions in user Lisp packages have a loop that
+does a certain amount of processing each time around, and exits when
+@code{(input-pending-p)} is non-@code{nil}. That approach seems very
+natural but has two problems:
+
+@itemize
+@item
+It blocks out all process output (since Emacs accepts process output
+only while waiting).
+
+@item
+It blocks out any idle timers that ought to run during that time.
+@end itemize
+
+@noindent
+To avoid these problems, don't use that technique. Instead, write
+such idle timers to reschedule themselves after a brief pause, using
+the method in the @code{timer-function} example above.
+
@node Terminal Input
@section Terminal Input
@cindex terminal input
@menu
* Input Modes:: Options for how input is processed.
-* Translating Input:: Low level conversion of some characters or events
- into others.
* Recording Input:: Saving histories of recent or all input events.
@end menu
@end table
@end defun
-@node Translating Input
-@subsection Translating Input Events
-@cindex translating input events
-
- This section describes features for translating input events into
-other input events before they become part of key sequences. These
-features apply to each event in the order they are described here: each
-event is first modified according to @code{extra-keyboard-modifiers},
-then translated through @code{keyboard-translate-table} (if applicable),
-and finally decoded with the specified keyboard coding system. If it is
-being read as part of a key sequence, it is then added to the sequence
-being read; then subsequences containing it are checked first with
-@code{function-key-map} and then with @code{key-translation-map}.
-
-@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
-character matter. Each time the user types a keyboard key, it is
-altered as if those modifier keys were held down. For instance, if
-you bind @code{extra-keyboard-modifiers} to @code{?\C-\M-a}, then all
-keyboard input characters typed during the scope of the binding will
-have the control and meta modifiers applied to them. The character
-@code{?\C-@@}, equivalent to the integer 0, does not count as a control
-character for this purpose, but as a character with no modifiers.
-Thus, setting @code{extra-keyboard-modifiers} to zero cancels any
-modification.
-
-When using a window system, the program can ``press'' any of the
-modifier keys in this way. Otherwise, only the @key{CTL} and @key{META}
-keys can be virtually pressed.
-
-Note that this variable applies only to events that really come from
-the keyboard, and has no effect on mouse events or any other events.
-@end defvar
-
-@defvar keyboard-translate-table
-This variable is the translate table for keyboard characters. It lets
-you reshuffle the keys on the keyboard without changing any command
-bindings. Its value is normally a char-table, or else @code{nil}.
-(It can also be a string or vector, but this is considered obsolete.)
-
-If @code{keyboard-translate-table} is a char-table
-(@pxref{Char-Tables}), then each character read from the keyboard is
-looked up in this char-table. If the value found there is
-non-@code{nil}, then it is used instead of the actual input character.
-
-Note that this translation is the first thing that happens to a
-character after it is read from the terminal. Record-keeping features
-such as @code{recent-keys} and dribble files record the characters after
-translation.
-
-Note also that this translation is done before the characters are
-supplied to input methods (@pxref{Input Methods}). Use
-@code{translation-table-for-input} (@pxref{Translation of Characters}),
-if you want to translate characters after input methods operate.
-@end defvar
-
-@defun keyboard-translate from to
-This function modifies @code{keyboard-translate-table} to translate
-character code @var{from} into character code @var{to}. It creates
-the keyboard translate table if necessary.
-@end defun
-
- Here's an example of using the @code{keyboard-translate-table} to
-make @kbd{C-x}, @kbd{C-c} and @kbd{C-v} perform the cut, copy and paste
-operations:
-
-@example
-(keyboard-translate ?\C-x 'control-x)
-(keyboard-translate ?\C-c 'control-c)
-(keyboard-translate ?\C-v 'control-v)
-(global-set-key [control-x] 'kill-region)
-(global-set-key [control-c] 'kill-ring-save)
-(global-set-key [control-v] 'yank)
-@end example
-
-@noindent
-On a graphical terminal that supports extended @acronym{ASCII} input,
-you can still get the standard Emacs meanings of one of those
-characters by typing it with the shift key. That makes it a different
-character as far as keyboard translation is concerned, but it has the
-same usual meaning.
-
- The remaining translation features translate subsequences of key
-sequences being read. They are implemented in @code{read-key-sequence}
-and have no effect on input read with @code{read-event}.
-
-@defvar function-key-map
-This variable holds a keymap that describes the character sequences sent
-by function keys on an ordinary character terminal. This keymap has the
-same structure as other keymaps, but is used differently: it specifies
-translations to make while reading key sequences, rather than bindings
-for key sequences.
-
-If @code{function-key-map} ``binds'' a key sequence @var{k} to a vector
-@var{v}, then when @var{k} appears as a subsequence @emph{anywhere} in a
-key sequence, it is replaced with the events in @var{v}.
-
-For example, VT100 terminals send @kbd{@key{ESC} O P} when the
-keypad @key{PF1} key is pressed. Therefore, we want Emacs to translate
-that sequence of events into the single event @code{pf1}. We accomplish
-this by ``binding'' @kbd{@key{ESC} O P} to @code{[pf1]} in
-@code{function-key-map}, when using a VT100.
-
-Thus, typing @kbd{C-c @key{PF1}} sends the character sequence @kbd{C-c
-@key{ESC} O P}; later the function @code{read-key-sequence} translates
-this back into @kbd{C-c @key{PF1}}, which it returns as the vector
-@code{[?\C-c pf1]}.
-
-Entries in @code{function-key-map} are ignored if they conflict with
-bindings made in the minor mode, local, or global keymaps. The intent
-is that the character sequences that function keys send should not have
-command bindings in their own right---but if they do, the ordinary
-bindings take priority.
-
-The value of @code{function-key-map} is usually set up automatically
-according to the terminal's Terminfo or Termcap entry, but sometimes
-those need help from terminal-specific Lisp files. Emacs comes with
-terminal-specific files for many common terminals; their main purpose is
-to make entries in @code{function-key-map} beyond those that can be
-deduced from Termcap and Terminfo. @xref{Terminal-Specific}.
-@end defvar
-
-@defvar key-translation-map
-This variable is another keymap used just like @code{function-key-map}
-to translate input events into other events. It differs from
-@code{function-key-map} in two ways:
-
-@itemize @bullet
-@item
-@code{key-translation-map} goes to work after @code{function-key-map} is
-finished; it receives the results of translation by
-@code{function-key-map}.
-
-@item
-Non-prefix bindings in @code{key-translation-map} override actual key
-bindings. For example, if @kbd{C-x f} has a non-prefix binding in
-@code{key-translation-map}, that translation takes effect even though
-@kbd{C-x f} also has a key binding in the global map.
-@end itemize
-
-Note however that actual key bindings can have an effect on
-@code{key-translation-map}, even though they are overridden by it.
-Indeed, actual key bindings override @code{function-key-map} and thus
-may alter the key sequence that @code{key-translation-map} receives.
-Clearly, it is better to avoid this type of situation.
-
-The intent of @code{key-translation-map} is for users to map one
-character set to another, including ordinary characters normally bound
-to @code{self-insert-command}.
-@end defvar
-
-@cindex key translation function
-You can use @code{function-key-map} or @code{key-translation-map} for
-more than simple aliases, by using a function, instead of a key
-sequence, as the ``translation'' of a key. Then this function is called
-to compute the translation of that key.
-
-The key translation function receives one argument, which is the prompt
-that was specified in @code{read-key-sequence}---or @code{nil} if the
-key sequence is being read by the editor command loop. In most cases
-you can ignore the prompt value.
-
-If the function reads input itself, it can have the effect of altering
-the event that follows. For example, here's how to define @kbd{C-c h}
-to turn the character that follows into a Hyper character:
-
-@example
-@group
-(defun hyperify (prompt)
- (let ((e (read-event)))
- (vector (if (numberp e)
- (logior (lsh 1 24) e)
- (if (memq 'hyper (event-modifiers e))
- e
- (add-event-modifier "H-" e))))))
-
-(defun add-event-modifier (string e)
- (let ((symbol (if (symbolp e) e (car e))))
- (setq symbol (intern (concat string
- (symbol-name symbol))))
-@end group
-@group
- (if (symbolp e)
- symbol
- (cons symbol (cdr e)))))
-
-(define-key function-key-map "\C-ch" 'hyperify)
-@end group
-@end example
-
-Finally, if you have enabled keyboard character set decoding using
-@code{set-keyboard-coding-system}, decoding is done after the
-translations listed above. @xref{Terminal I/O Encoding}. In future
-Emacs versions, character set decoding may be done before the other
-translations.
-
@node Recording Input
@subsection Recording Input
+@cindex recording input
@defun recent-keys
-This function returns a vector containing the last 100 input events from
+This function returns a vector containing the last 300 input events from
the keyboard or mouse. All input events are included, whether or not
they were used as parts of key sequences. Thus, you always get the last
100 input events, not counting events generated by keyboard macros.
This variable's value is the output speed of the terminal, as far as
Emacs knows. Setting this variable does not change the speed of actual
data transmission, but the value is used for calculations such as
-padding. It also affects decisions about whether to scroll part of the
-screen or repaint---even when using a window system. (We designed it
-this way despite the fact that a window system has no true ``output
-speed'', to give you a way to tune these decisions.)
+padding.
+
+ It also affects decisions about whether to scroll part of the
+screen or repaint on text terminals. @xref{Forcing Redisplay},
+for the corresponding functionality on graphical terminals.
The value is measured in baud.
@end defvar
The sound must be stored as a file in RIFF-WAVE format (@samp{.wav})
or Sun Audio format (@samp{.au}).
-@tindex play-sound
@defun play-sound sound
This function plays a specified sound. The argument, @var{sound}, has
the form @code{(sound @var{properties}...)}, where the @var{properties}
@end defun
@defun play-sound-file file &optional volume device
-@tindex play-sound-file
This function is an alternative interface to playing a sound @var{file}
specifying an optional @var{volume} and @var{device}.
@end defun
-@tindex play-sound-functions
@defvar play-sound-functions
A list of functions to be called before playing a sound. Each function
is called with one argument, a property list that describes the sound.
@node X11 Keysyms
@section Operating on X11 Keysyms
+@cindex X11 keysyms
To define system-specific X11 keysyms, set the variable
@code{system-key-alist}.
@node Batch Mode
@section Batch Mode
@cindex batch mode
-@cindex noninteractive use
The command-line option @samp{-batch} causes Emacs to run
noninteractively. In this mode, Emacs does not read commands from the
@var{session}}.
@defvar emacs-save-session-functions
-@tindex emacs-save-session-functions
Emacs supports saving state by using a hook called
@code{emacs-save-session-functions}. Each function in this hook is
called when the session manager tells Emacs that the window system is