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lispref.info-35
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GNU Info File
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1995-09-01
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This is Info file ../../info/lispref.info, produced by Makeinfo-1.63
from the input file lispref.texi.
Edition History:
GNU Emacs Lisp Reference Manual Second Edition (v2.01), May 1993 GNU
Emacs Lisp Reference Manual Further Revised (v2.02), August 1993 Lucid
Emacs Lisp Reference Manual (for 19.10) First Edition, March 1994
XEmacs Lisp Programmer's Manual (for 19.12) Second Edition, April 1995
GNU Emacs Lisp Reference Manual v2.4, June 1995 XEmacs Lisp
Programmer's Manual (for 19.13) Third Edition, July 1995
Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995 Free Software
Foundation, Inc. Copyright (C) 1994, 1995 Sun Microsystems, Inc.
Copyright (C) 1995 Amdahl Corporation. Copyright (C) 1995 Ben Wing.
Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.
Permission is granted to copy and distribute modified versions of
this manual under the conditions for verbatim copying, 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 this permission notice may be stated in a
translation approved by the Foundation.
Permission is granted to copy and distribute modified versions of
this manual under the conditions for verbatim copying, provided also
that the section entitled "GNU General Public License" is 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 section entitled "GNU General Public License"
may be included in a translation approved by the Free Software
Foundation instead of in the original English.
File: lispref.info, Node: Time Conversion, Next: Timers, Prev: Time of Day, Up: System Interface
Time Conversion
===============
These functions convert time values (lists of two or three integers)
to strings or to calendrical information. There is also a function to
convert calendrical information to a time value. You can get time
values from the functions `current-time' (*note Time of Day::.) and
`file-attributes' (*note File Attributes::.).
- Function: format-time-string FORMAT-STRING TIME
This function converts TIME to a string according to
FORMAT-STRING. The argument FORMAT-STRING may contain
`%'-sequences which say to substitute parts of the time. Here is a
table of what the `%'-sequences mean:
`%a'
This stands for the abbreviated name of the day of week.
`%A'
This stands for the full name of the day of week.
`%b'
This stands for the abbreviated name of the month.
`%B'
This stands for the full name of the month.
`%c'
This is a synonym for `%x %X'.
`%C'
This has a locale-specific meaning. In the default locale
(named C), it is equivalent to `%A, %B %e, %Y'.
`%d'
This stands for the day of month, zero-padded.
`%D'
This is a synonym for `%m/%d/%y'.
`%e'
This stands for the day of month, blank-padded.
`%h'
This is a synonym for `%b'.
`%H'
This stands for the hour (00-23).
`%I'
This stands for the hour (00-12).
`%j'
This stands for the day of the year (001-366).
`%k'
This stands for the hour (0-23), blank padded.
`%l'
This stands for the hour (1-12), blank padded.
`%m'
This stands for the month (01-12).
`%M'
This stands for the minute (00-59).
`%n'
This stands for a newline.
`%p'
This stands for `AM' or `PM', as appropriate.
`%r'
This is a synonym for `%I:%M:%S %p'.
`%R'
This is a synonym for `%H:%M'.
`%S'
This stands for the seconds (00-60).
`%t'
This stands for a tab character.
`%T'
This is a synonym for `%H:%M:%S'.
`%U'
This stands for the week of the year (01-52), assuming that
weeks start on Sunday.
`%w'
This stands for the numeric day of week (0-6). Sunday is day
0.
`%W'
This stands for the week of the year (01-52), assuming that
weeks start on Monday.
`%x'
This has a locale-specific meaning. In the default locale
(named C), it is equivalent to `%D'.
`%X'
This has a locale-specific meaning. In the default locale
(named C), it is equivalent to `%T'.
`%y'
This stands for the year without century (00-99).
`%Y'
This stands for the year with century.
`%Z'
This stands for the time zone abbreviation.
- Function: decode-time TIME
This function converts a time value into calendrical information.
The return value is a list of nine elements, as follows:
(SECONDS MINUTES HOUR DAY MONTH YEAR DOW DST ZONE)
Here is what the elements mean:
SEC
The number of seconds past the minute, as an integer between
0 and 59.
MINUTE
The number of minutes past the hour, as an integer between 0
and 59.
HOUR
The hour of the day, as an integer between 0 and 23.
DAY
The day of the month, as an integer between 1 and 31.
MONTH
The month of the year, as an integer between 1 and 12.
YEAR
The year, an integer typically greater than 1900.
DOW
The day of week, as an integer between 0 and 6, where 0
stands for Sunday.
DST
`t' if daylight savings time is effect, otherwise `nil'.
ZONE
An integer indicating the time zone, as the number of seconds
east of Greenwich.
Note that Common Lisp has different meanings for DOW and ZONE.
- Function: encode-time SECONDS MINUTES HOUR DAY MONTH YEAR &optional
ZONE
This function is the inverse of `decode-time'. It converts seven
items of calendrical data into a time value. For the meanings of
the arguments, see the table above under `decode-time'.
Year numbers less than 100 are treated just like other year
numbers. If you want them to stand for years above 1900, you must
alter them yourself before you call `encode-time'.
The optional argument ZONE defaults to the current time zone and
its daylight savings time rules. If specified, it can be either a
list (as you would get from `current-time-zone') or an integer (as
you would get from `decode-time'). The specified zone is used
without any further alteration for daylight savings time.
File: lispref.info, Node: Timers, Next: Terminal Input, Prev: Time Conversion, Up: System Interface
Timers for Delayed Execution
============================
You can set up a timer to call a function at a specified future time.
- Function: add-timeout SECS FUNCTION OBJECT &optional RESIGNAL
This function adds a timeout, to be signaled after the timeout
period has elapsed. SECS is a number of seconds, expressed as an
integer or a float. FUNCTION will be called after that many
seconds have elapsed, with one argument, the given OBJECT. If the
optional RESIGNAL argument is provided, then after this timeout
expires, `add-timeout' will automatically be called again with
RESIGNAL as the first argument.
This function returns an object which is the "id" of this
particular timeout. You can pass that object to `disable-timeout'
to turn off the timeout before it has been signalled.
The number of seconds may be expressed as a floating-point number,
in which case some fractional part of a second will be used.
Caveat: the usable timeout granularity will vary from system to
system.
Adding a timeout causes a timeout event to be returned by
`next-event', and the function will be invoked by
`dispatch-event', so if XEmacs is in a tight loop, the function
will not be invoked until the next call to sit-for or until the
return to top-level (the same is true of process filters).
WARNING: if you are thinking of calling add-timeout from inside of
a callback function as a way of resignalling a timeout, think
again. There is a race condition. That's why the RESIGNAL
argument exists.
(NOTE: In FSF Emacs, this function is called `run-at-time' and has
different semantics.)
- Function: disable-timeout ID
Cancel the requested action for ID, which should be a value
previously returned by `add-timeout'. This cancels the effect of
that call to `add-timeout'; the arrival of the specified time will
not cause anything special to happen. (NOTE: In FSF Emacs, this
function is called `cancel-timer'.)
File: lispref.info, Node: Terminal Input, Next: Terminal Output, Prev: Timers, Up: System Interface
Terminal Input
==============
This section describes functions and variables for recording or
manipulating terminal input. See *Note Display::, for related
functions.
* 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.
File: lispref.info, Node: Input Modes, Next: Translating Input, Up: Terminal Input
Input Modes
-----------
- Function: set-input-mode INTERRUPT FLOW META QUIT-CHAR
This function sets the mode for reading keyboard input. If
INTERRUPT is non-null, then XEmacs uses input interrupts. If it is
`nil', then it uses CBREAK mode. When XEmacs communicates
directly with X, it ignores this argument and uses interrupts if
that is the way it knows how to communicate.
If FLOW is non-`nil', then XEmacs uses XON/XOFF (`C-q', `C-s')
flow control for output to the terminal. This has no effect except
in CBREAK mode. *Note Flow Control::.
The default setting is system dependent. Some systems always use
CBREAK mode regardless of what is specified.
The argument META controls support for input character codes above
127. If META is `t', XEmacs converts characters with the 8th bit
set into Meta characters. If META is `nil', XEmacs disregards the
8th bit; this is necessary when the terminal uses it as a parity
bit. If META is neither `t' nor `nil', XEmacs uses all 8 bits of
input unchanged. This is good for terminals using European 8-bit
character sets.
If QUIT-CHAR is non-`nil', it specifies the character to use for
quitting. Normally this character is `C-g'. *Note Quitting::.
The `current-input-mode' function returns the input mode settings
XEmacs is currently using.
- Function: current-input-mode
This function returns current mode for reading keyboard input. It
returns a list, corresponding to the arguments of `set-input-mode',
of the form `(INTERRUPT FLOW META QUIT)' in which:
INTERRUPT
is non-`nil' when XEmacs is using interrupt-driven input. If
`nil', Emacs is using CBREAK mode.
FLOW
is non-`nil' if XEmacs uses XON/XOFF (`C-q', `C-s') flow
control for output to the terminal. This value has no effect
unless INTERRUPT is non-`nil'.
META
is `t' if XEmacs treats the eighth bit of input characters as
the meta bit; `nil' means XEmacs clears the eighth bit of
every input character; any other value means XEmacs uses all
eight bits as the basic character code.
QUIT
is the character XEmacs currently uses for quitting, usually
`C-g'.
File: lispref.info, Node: Translating Input, Next: Recording Input, Prev: Input Modes, Up: Terminal Input
Translating Input Events
------------------------
This section describes features for translating input events into
other input events before they become part of key sequences.
- Variable: function-key-map
This variable holds a keymap that describes the character sequences
sent by function keys on an ordinary character terminal. This
keymap uses the same data structure as other keymaps, but is used
differently: it specifies translations to make while reading
events.
If `function-key-map' "binds" a key sequence K to a vector V, then
when K appears as a subsequence *anywhere* in a key sequence, it
is replaced with the events in V.
For example, VT100 terminals send `ESC O P' when the keypad PF1
key is pressed. Therefore, we want XEmacs to translate that
sequence of events into the single event `pf1'. We accomplish
this by "binding" `ESC O P' to `[pf1]' in `function-key-map', when
using a VT100.
Thus, typing `C-c PF1' sends the character sequence `C-c ESC O P';
later the function `read-key-sequence' translates this back into
`C-c PF1', which it returns as the vector `[?\C-c pf1]'.
Entries in `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.
The value of `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.
XEmacs comes with terminal-specific files for many common
terminals; their main purpose is to make entries in
`function-key-map' beyond those that can be deduced from Termcap
and Terminfo. *Note Terminal-Specific::.
Emacs versions 18 and earlier used totally different means of
detecting the character sequences that represent function keys.
The `iso-transl' library uses this feature to provide a way of
inputting non-ASCII Latin-1 characters.
File: lispref.info, Node: Recording Input, Prev: Translating Input, Up: Terminal Input
Recording Input
---------------
- Function: recent-keys
This function returns a vector containing the last 100 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 inputs, not counting keyboard macros.
(Events from keyboard macros are excluded because they are less
interesting for debugging; it should be enough to see the events
that invoked the macros.)
- Command: open-dribble-file FILENAME
This function opens a "dribble file" named FILENAME. When a
dribble file is open, each input event from the keyboard or mouse
(but not those from keyboard macros) is written in that file. A
non-character event is expressed using its printed representation
surrounded by `<...>'.
You close the dribble file by calling this function with an
argument of `nil'.
This function is normally used to record the input necessary to
trigger an XEmacs bug, for the sake of a bug report.
(open-dribble-file "~/dribble")
=> nil
See also the `open-termscript' function (*note Terminal Output::.).
File: lispref.info, Node: Terminal Output, Next: Flow Control, Prev: Terminal Input, Up: System Interface
Terminal Output
===============
The terminal output functions send output to the terminal or keep
track of output sent to the terminal. The variable `baud-rate' tells
you what XEmacs thinks is the output speed of the terminal.
- Variable: baud-rate
This variable's value is the output speed of the terminal, as far
as XEmacs 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.)
The value is measured in baud.
If you are running across a network, and different parts of the
network work at different baud rates, the value returned by XEmacs may
be different from the value used by your local terminal. Some network
protocols communicate the local terminal speed to the remote machine, so
that XEmacs and other programs can get the proper value, but others do
not. If XEmacs has the wrong value, it makes decisions that are less
than optimal. To fix the problem, set `baud-rate'.
- Function: baud-rate
This function returns the value of the variable `baud-rate'. In
Emacs versions 18 and earlier, this was the only way to find out
the terminal speed.
- Function: send-string-to-terminal STRING
This function sends STRING to the terminal without alteration.
Control characters in STRING have terminal-dependent effects.
One use of this function is to define function keys on terminals
that have downloadable function key definitions. For example,
this is how on certain terminals to define function key 4 to move
forward four characters (by transmitting the characters `C-u C-f'
to the computer):
(send-string-to-terminal "\eF4\^U\^F")
=> nil
- Command: open-termscript FILENAME
This function is used to open a "termscript file" that will record
all the characters sent by XEmacs to the terminal. It returns
`nil'. Termscript files are useful for investigating problems
where XEmacs garbles the screen, problems that are due to incorrect
Termcap entries or to undesirable settings of terminal options more
often than to actual XEmacs bugs. Once you are certain which
characters were actually output, you can determine reliably
whether they correspond to the Termcap specifications in use.
See also `open-dribble-file' in *Note Terminal Input::.
(open-termscript "../junk/termscript")
=> nil
File: lispref.info, Node: Flow Control, Next: Batch Mode, Prev: Terminal Output, Up: System Interface
Flow Control
============
This section attempts to answer the question "Why does XEmacs choose
to use flow-control characters in its command character set?" For a
second view on this issue, read the comments on flow control in the
`emacs/INSTALL' file from the distribution; for help with Termcap
entries and DEC terminal concentrators, see `emacs/etc/TERMS'.
At one time, most terminals did not need flow control, and none used
`C-s' and `C-q' for flow control. Therefore, the choice of `C-s' and
`C-q' as command characters was uncontroversial. XEmacs, for economy
of keystrokes and portability, used nearly all the ASCII control
characters, with mnemonic meanings when possible; thus, `C-s' for
search and `C-q' for quote.
Later, some terminals were introduced which required these characters
for flow control. They were not very good terminals for full-screen
editing, so XEmacs maintainers did not pay attention. In later years,
flow control with `C-s' and `C-q' became widespread among terminals,
but by this time it was usually an option. And the majority of users,
who can turn flow control off, were unwilling to switch to less
mnemonic key bindings for the sake of flow control.
So which usage is "right", XEmacs's or that of some terminal and
concentrator manufacturers? This question has no simple answer.
One reason why we are reluctant to cater to the problems caused by
`C-s' and `C-q' is that they are gratuitous. There are other
techniques (albeit less common in practice) for flow control that
preserve transparency of the character stream. Note also that their use
for flow control is not an official standard. Interestingly, on the
model 33 teletype with a paper tape punch (which is very old), `C-s'
and `C-q' were sent by the computer to turn the punch on and off!
As X servers and other window systems replace character-only
terminals, this problem is gradually being cured. For the mean time,
XEmacs provides a convenient way of enabling flow control if you want
it: call the function `enable-flow-control'.
- Function: enable-flow-control
This function enables use of `C-s' and `C-q' for output flow
control, and provides the characters `C-\' and `C-^' as aliases
for them using `keyboard-translate-table' (*note Translating
Input::.).
You can use the function `enable-flow-control-on' in your `.emacs'
file to enable flow control automatically on certain terminal types.
- Function: enable-flow-control-on &rest TERMTYPES
This function enables flow control, and the aliases `C-\' and
`C-^', if the terminal type is one of TERMTYPES. For example:
(enable-flow-control-on "vt200" "vt300" "vt101" "vt131")
Here is how `enable-flow-control' does its job:
1. It sets CBREAK mode for terminal input, and tells the operating
system to handle flow control, with `(set-input-mode nil t)'.
2. It sets up `keyboard-translate-table' to translate `C-\' and `C-^'
into `C-s' and `C-q'. Except at its very lowest level, XEmacs
never knows that the characters typed were anything but `C-s' and
`C-q', so you can in effect type them as `C-\' and `C-^' even when
they are input for other commands. *Note Translating Input::.
If the terminal is the source of the flow control characters, then
once you enable kernel flow control handling, you probably can make do
with less padding than normal for that terminal. You can reduce the
amount of padding by customizing the Termcap entry. You can also
reduce it by setting `baud-rate' to a smaller value so that XEmacs uses
a smaller speed when calculating the padding needed. *Note Terminal
Output::.
File: lispref.info, Node: Batch Mode, Prev: Flow Control, Up: System Interface
Batch Mode
==========
The command line option `-batch' causes XEmacs to run
noninteractively. In this mode, XEmacs does not read commands from the
terminal, it does not alter the terminal modes, and it does not expect
to be outputting to an erasable screen. The idea is that you specify
Lisp programs to run; when they are finished, XEmacs should exit. The
way to specify the programs to run is with `-l FILE', which loads the
library named FILE, and `-f FUNCTION', which calls FUNCTION with no
arguments.
Any Lisp program output that would normally go to the echo area,
either using `message' or using `prin1', etc., with `t' as the stream,
goes instead to XEmacs's standard error descriptor when in batch mode.
Thus, XEmacs behaves much like a noninteractive application program.
(The echo area output that XEmacs itself normally generates, such as
command echoing, is suppressed entirely.)
- Variable: noninteractive
This variable is non-`nil' when XEmacs is running in batch mode.
File: lispref.info, Node: X-Windows, Next: ToolTalk Support, Prev: System Interface, Up: Top
Functions Specific to the X Window System
*****************************************
XEmacs provides the concept of "devices", which generalizes
connections to an X server, a TTY device, etc. Most information about
an X server that XEmacs is connected to can be determined through
general device functions. *Note Devices::. However, there are some
features of the X Window System that do not generalize well, and they
are covered specially here.
* Menu:
* X Selections:: Transferring text to and from other X clients.
* X Server:: Information about the X server connected to
a particular device.
* X Miscellaneous:: Other X-specific functions and variables.
File: lispref.info, Node: X Selections, Next: X Server, Up: X-Windows
X Selections
============
The X server records a set of "selections" which permit transfer of
data between application programs. The various selections are
distinguished by "selection types", represented in XEmacs by symbols.
X clients including XEmacs can read or set the selection for any given
type.
- Function: x-own-selection DATA &optional TYPE
This function sets a "selection" in the X server. It takes two
arguments: a value, DATA, and the selection type TYPE to assign it
to. DATA may be a string, a cons of two markers, or an extent.
In the latter cases, the selection is considered to be the text
between the markers, or between the extent's endpoints.
Each possible TYPE has its own selection value, which changes
independently. The usual values of TYPE are `PRIMARY' and
`SECONDARY'; these are symbols with upper-case names, in accord
with X Windows conventions. The default is `PRIMARY'.
(In FSF Emacs, this function is called `x-set-selection' and takes
different arguments.)
- Function: x-get-selection
This function accesses selections set up by XEmacs or by other X
clients. It returns the value of the current primary selection.
- Function: x-disown-selection &optional SECONDARY-P
Assuming we own the selection, this function disowns it. If
SECONDARY-P is non-`nil', the secondary selection instead of the
primary selection is discarded.
The X server also has a set of numbered "cut buffers" which can
store text or other data being moved between applications. Cut buffers
are considered obsolete, but XEmacs supports them for the sake of X
clients that still use them.
- Function: x-get-cutbuffer &optional N
This function returns the contents of cut buffer number N. (This
function is called `x-get-cut-buffer' in FSF Emacs.)
- Function: x-store-cutbuffer STRING
This function stores STRING into the first cut buffer (cut buffer
0), moving the other values down through the series of cut buffers,
kill-ring-style. (This function is called `x-set-cut-buffer' in FSF
Emacs.)
File: lispref.info, Node: X Server, Next: X Miscellaneous, Prev: X Selections, Up: X-Windows
X Server
========
This section describes how to access and change the overall status of
the X server XEmacs is using.
* Menu:
* Resources:: Getting resource values from the server.
* Server Data:: Getting info about the X server.
* Grabs:: Restricting access to the server by other apps.
File: lispref.info, Node: Resources, Next: Server Data, Up: X Server
Resources
---------
- Function: default-x-device
This function return the default X device for resourcing. This is
the first-created X device that still exists.
- Function: x-get-resource NAME CLASS TYPE &optional LOCALE DEVICE
NOERROR
This function retrieves a resource value from the X resource
manager.
* The first arg is the name of the resource to retrieve, such as
`"font"'.
* The second arg is the class of the resource to retrieve, like
`"Font"'.
* The third arg should be one of the symbols `string',
`integer', `natnum', or `boolean', specifying the type of
object that the database is searched for.
* The fourth arg is the locale to search for the resources on,
and can currently be a a buffer, a frame, a device, or the
symbol `global'. If omitted, it defaults to `global'.
* The fifth arg is the device to search for the resources on.
(The resource database for a particular device is constructed
by combining non-device- specific resources such any
command-line resources specified and any app-defaults files
found [or the fallback resources supplied by XEmacs, if no
app-defaults file is found] with device-specific resources
such as those supplied using `xrdb'.) If omitted, it defaults
to the device of LOCALE, if a device can be derived (i.e. if
LOCALE is a frame or device), and otherwise defaults to the
value of `default-x-device'.
* The sixth arg NOERROR, if non-`nil', means do not signal an
error if a bogus resource specification was retrieved (e.g.
if a non-integer was given when an integer was requested).
In this case, a warning is issued instead.
The resource names passed to this function are looked up relative
to the locale.
If you want to search for a subresource, you just need to specify
the resource levels in NAME and CLASS. For example, NAME could be
`"modeline.attributeFont"', and CLASS `"Face.AttributeFont"'.
Specifically,
1. If LOCALE is a buffer, a call
`(x-get-resource "foreground" "Foreground" 'string SOME-BUFFER)'
is an interface to a C call something like
`XrmGetResource (db, "xemacs.buffer.BUFFER-NAME.foreground",
"Emacs.EmacsLocaleType.EmacsBuffer.Foreground",
"String");'
2. If LOCALE is a frame, a call
`(x-get-resource "foreground" "Foreground" 'string SOME-FRAME)'
is an interface to a C call something like
`XrmGetResource (db, "xemacs.frame.FRAME-NAME.foreground",
"Emacs.EmacsLocaleType.EmacsFrame.Foreground",
"String");'
3. If LOCALE is a device, a call
`(x-get-resource "foreground" "Foreground" 'string SOME-DEVICE)'
is an interface to a C call something like
`XrmGetResource (db, "xemacs.device.DEVICE-NAME.foreground",
"Emacs.EmacsLocaleType.EmacsDevice.Foreground",
"String");'
4. If LOCALE is the symbol `global', a call
`(x-get-resource "foreground" "Foreground" 'string 'global)'
is an interface to a C call something like
`XrmGetResource (db, "xemacs.foreground",
"Emacs.Foreground",
"String");'
Note that for `global', no prefix is added other than that of the
application itself; thus, you can use this locale to retrieve
arbitrary application resources, if you really want to.
The returned value of this function is `nil' if the queried
resource is not found. If TYPE is `string', a string is returned,
and if it is `integer', an integer is returned. If TYPE is
`boolean', then the returned value is the list `(t)' for true,
`(nil)' for false, and is `nil' to mean "unspecified".
- Function: x-put-resource RESOURCE-LINE &optional DEVICE
This function adds a resource to the resource database for DEVICE.
RESOURCE-LINE specifies the resource to add and should be a
standard resource specification.
- Variable: x-emacs-application-class
This variable holds The X application class of the XEmacs process.
This controls, among other things, the name of the "app-defaults"
file that XEmacs will use. For changes to this variable to take
effect, they must be made before the connection to the X server is
initialized, that is, this variable may only be changed before
XEmacs is dumped, or by setting it in the file
`lisp/term/x-win.el'.
File: lispref.info, Node: Server Data, Next: Grabs, Prev: Resources, Up: X Server
Data about the X Server
-----------------------
This section describes functions and a variable that you can use to
get information about the capabilities and origin of the X server
corresponding to a particular device. The device argument is generally
optional and defaults to the selected device.
- Function: x-server-version &optional DEVICE
This function returns the list of version numbers of the X server
DEVICE is on. The returned value is a list of three integers: the
major and minor version numbers of the X protocol in use, and the
vendor-specific release number.
- Function: x-server-vendor &optional DEVICE
This function returns the vendor supporting the X server DEVICE is
on.
- Function: x-display-visual-class &optional DEVICE
This function returns the visual class of the display DEVICE is
on. The value is one of the symbols `static-gray', `gray-scale',
`static-color', `pseudo-color', `true-color', and `direct-color'.
(Note that this is different from previous versions of XEmacs,
which returned `StaticGray', `GrayScale', etc.)
File: lispref.info, Node: Grabs, Prev: Server Data, Up: X Server
Restricting Access to the Server by Other Apps
----------------------------------------------
- Function: x-grab-keyboard &optional DEVICE
This function grabs the keyboard on the given device (defaulting
to the selected one). So long as the keyboard is grabbed, all
keyboard events will be delivered to XEmacs - it is not possible
for other X clients to eavesdrop on them. Ungrab the keyboard
with `x-ungrab-keyboard' (use an `unwind-protect'). Returns `t'
if the grab was successful; `nil' otherwise.
- Function: x-ungrab-keyboard &optional DEVICE
This function releases a keyboard grab made with `x-grab-keyboard'.
- Function: x-grab-pointer &optional DEVICE CURSOR IGNORE-KEYBOARD
This function grabs the pointer and restricts it to its current
window. If optional DEVICE argument is `nil', the selected device
will be used. If optional CURSOR argument is non-`nil', change
the pointer shape to that until `x-ungrab-pointer' is called (it
should be an object returned by the `make-cursor' function). If
the second optional argument IGNORE-KEYBOARD is non-`nil', ignore
all keyboard events during the grab. Returns `t' if the grab is
successful, `nil' otherwise.
- Function: x-ungrab-pointer &optional DEVICE
This function releases a pointer grab made with `x-grab-pointer'.
If optional first arg DEVICE is `nil' the selected device is used.
If it is `t' the pointer will be released on all X devices.
File: lispref.info, Node: X Miscellaneous, Prev: X Server, Up: X-Windows
Miscellaneous X Functions and Variables
=======================================
- Variable: x-bitmap-file-path
This variable holds a list of the directories in which X bitmap
files may be found. If `nil', this is initialized from the
`"*bitmapFilePath"' resource. This is used by the
`make-image-instance' function (however, note that if the
environment variable `XBMLANGPATH' is set, it is consulted first).
- Variable: x-library-search-path
This variable holds the search path used by `read-color' to find
`rgb.txt'.
- Function: x-valid-keysym-name-p KEYSYM
This function returns true if KEYSYM names a keysym that the X
library knows about. Valid keysyms are listed in the files
`/usr/include/X11/keysymdef.h' and in `/usr/lib/X11/XKeysymDB', or
whatever the equivalents are on your system.
- Function: x-window-id &optional FRAME
This function returns the ID of the X11 window. This gives us a
chance to manipulate the Emacs window from within a different
program. Since the ID is an unsigned long, we return it as a
string.
- Variable: x-allow-sendevents
If non-`nil', synthetic events are allowed. `nil' means they are
ignored. Beware: allowing XEmacs to process SendEvents opens a
big security hole.
- Function: x-debug-mode ARG &optional DEVICE
With a true arg, make the connection to the X server synchronous.
With false, make it asynchronous. Synchronous connections are
much slower, but are useful for debugging. (If you get X errors,
make the connection synchronous, and use a debugger to set a
breakpoint on `x_error_handler'. Your backtrace of the C stack
will now be useful. In asynchronous mode, the stack above
`x_error_handler' isn't helpful because of buffering.) If DEVICE
is not specified, the selected device is assumed.
Calling this function is the same as calling the C function
`XSynchronize', or starting the program with the `-sync' command
line argument.
- Variable: x-debug-events
If non-zero, debug information about events that XEmacs sees is
displayed. Information is displayed on stderr. Currently defined
values are:
* 1 == non-verbose output
* 2 == verbose output
File: lispref.info, Node: ToolTalk Support, Next: Internationalization, Prev: X-Windows, Up: Top
ToolTalk Support
****************
* Menu:
* XEmacs ToolTalk API Summary::
* Sending Messages::
* Receiving Messages::
File: lispref.info, Node: XEmacs ToolTalk API Summary, Next: Sending Messages, Up: ToolTalk Support
XEmacs ToolTalk API Summary
===========================
The Emacs Lisp interface to ToolTalk is similar, at least in spirit,
to the standard C ToolTalk API. Only the message and pattern parts of
the API are supported at present; more of the API could be added if
needed. The Lisp interface departs from the C API in a few ways:
* ToolTalk is initialized automatically at XEmacs startup-time.
Messages can only be sent other ToolTalk applications connected to
the same X11 server that XEmacs is running on.
* There are fewer entry points; polymorphic functions with keyword
arguments are used instead.
* The callback interface is simpler and marginally less functional.
A single callback may be associated with a message or a pattern;
the callback is specified with a Lisp symbol (the symbol should
have a function binding).
* The session attribute for messages and patterns is always
initialized to the default session.
* Anywhere a ToolTalk enum constant, e.g. `TT_SESSION', is valid, one
can substitute the corresponding symbol, e.g. `'TT_SESSION'. This
simplifies building lists that represent messages and patterns.
File: lispref.info, Node: Sending Messages, Next: Receiving Messages, Prev: XEmacs ToolTalk API Summary, Up: ToolTalk Support
Sending Messages
================
* Menu:
* Example of Sending Messages::
* Elisp Interface for Sending Messages::
File: lispref.info, Node: Example of Sending Messages, Next: Elisp Interface for Sending Messages, Up: Sending Messages
Example of Sending Messages
---------------------------
Here's a simple example that sends a query to another application
and then displays its reply. Both the query and the reply are stored
in the first argument of the message.
(defun tooltalk-random-query-handler (msg)
(let ((state (get-tooltalk-message-attribute msg 'state)))
(cond
((eq state 'TT_HANDLED)
(message (get-tooltalk-message-attribute msg arg_val 0)))
((memq state '(TT_FAILED TT_REJECTED))
(message "Random query turns up nothing")))))
(defvar random-query-message
'( class TT_REQUEST
scope TT_SESSION
address TT_PROCEDURE
op "random-query"
args '((TT_INOUT "?" "string"))
callback tooltalk-random-query-handler))
(let ((m (make-tooltalk-message random-query-message)))
(send-tooltalk-message m))
File: lispref.info, Node: Elisp Interface for Sending Messages, Prev: Example of Sending Messages, Up: Sending Messages
Elisp Interface for Sending Messages
------------------------------------
- Function: make-tooltalk-message ATTRIBUTES
Create a ToolTalk message and initialize its attributes. The
value of ATTRIBUTES must be a list of alternating keyword/values,
where keywords are symbols that name valid message attributes.
For example:
(make-tooltalk-message
'(class TT_NOTICE
scope TT_SESSION
address TT_PROCEDURE
op "do-something"
args ("arg1" 12345 (TT_INOUT "arg3" "string"))))
Values must always be strings, integers, or symbols that represent
ToolTalk constants. Attribute names are the same as those
supported by `set-tooltalk-message-attribute', plus `args'.
The value of `args' should be a list of message arguments where
each message argument has the following form:
`(mode [value [type]])' or just `value'
Where MODE is one of `TT_IN', `TT_OUT', or `TT_INOUT' and TYPE is
a string. If TYPE isn't specified then `int' is used if VALUE is
a number; otherwise `string' is used. If TYPE is `string' then
VALUE is converted to a string (if it isn't a string already) with
`prin1-to-string'. If only a value is specified then MODE
defaults to `TT_IN'. If MODE is `TT_OUT' then VALUE and TYPE
don't need to be specified. You can find out more about the
semantics and uses of ToolTalk message arguments in chapter 4 of
the `ToolTalk Programmer's Guide'.
- Function: send-tooltalk-message MSG
Send the message on its way. Once the message has been sent it's
almost always a good idea to get rid of it with
`destroy-tooltalk-message'.
- Function: return-tooltalk-message MSG &optional MODE
Send a reply to this message. The second argument can be `reply',
`reject' or `fail'; the default is `reply'. Before sending a
reply, all message arguments whose mode is `TT_INOUT' or `TT_OUT'
should have been filled in - see `set-tooltalk-message-attribute'.
- Function: get-tooltalk-message-attribute MSG ATTRIBUTE &optional ARGN
Returns the indicated ToolTalk message attribute. Attributes are
identified by symbols with the same name (underscores and all) as
the suffix of the ToolTalk `tt_message_<attribute>' function that
extracts the value. String attribute values are copied and
enumerated type values (except disposition) are converted to
symbols; e.g. `TT_HANDLER' is `'TT_HANDLER', `uid' and `gid' are
represented by fixnums (small integers), `opnum' is converted to a
string, and `disposition' is converted to a fixnum. We convert
`opnum' (a C int) to a string (e.g. `123' => `"123"') because
there's no guarantee that opnums will fit within the range of
Emacs Lisp integers.
[TBD] Use the `plist' attribute instead of C API `user' attribute
for user-defined message data. To retrieve the value of a message
property, specify the indicator for ARGN. For example, to get the
value of a property called `rflag', use
(get-tooltalk-message-attribute msg 'plist 'rflag)
To get the value of a message argument use one of the `arg_val'
(strings), `arg_ival' (integers), or `arg_bval' (strings with
embedded nulls), attributes. For example, to get the integer
value of the third argument:
(get-tooltalk-message-attribute msg 'arg_ival 2)
As you can see, argument numbers are zero-based. The type of each
arguments can be retrieved with the `arg_type' attribute; however
ToolTalk doesn't define any semantics for the string value of
`arg_type'. Conventionally `string' is used for strings and `int'
for 32 bit integers. Note that Emacs Lisp stores the lengths of
strings explicitly (unlike C) so treating the value returned by
`arg_bval' like a string is fine.
- Function: set-tooltalk-message-attribute VALUE MSG ATTRIBUTE
&optional ARGN
Initialize one ToolTalk message attribute.
Attribute names and values are the same as for
`get-tooltalk-message-attribute'. A property list is provided for
user data (instead of the `user' message attribute); see
`get-tooltalk-message-attribute'.
Callbacks are handled slightly differently than in the C ToolTalk
API. The value of CALLBACK should be the name of a function of one
argument. It will be called each time the state of the message
changes. This is usually used to notice when the message's state
has changed to `TT_HANDLED' (or `TT_FAILED'), so that reply
argument values can be used.
If one of the argument attributes is specified as `arg_val',
`arg_ival', or `arg_bval', then ARGN must be the number of an
already created argument. Arguments can be added to a message
with `add-tooltalk-message-arg'.
- Function: add-tooltalk-message-arg MSG MODE TYPE &optional VALUE
Append one new argument to the message. MODE must be one of
`TT_IN', `TT_INOUT', or `TT_OUT', TYPE must be a string, and VALUE
can be a string or an integer. ToolTalk doesn't define any
semantics for TYPE, so only the participants in the protocol
you're using need to agree what types mean (if anything).
Conventionally `string' is used for strings and `int' for 32 bit
integers. Arguments can initialized by providing a value or with
`set-tooltalk-message-attribute'; the latter is neccessary if you
want to initialize the argument with a string that can contain
embedded nulls (use `arg_bval').
- Function: create-tooltalk-message
Create a new ToolTalk message. The message's session attribute is
initialized to the default session. Other attributes can be
intialized with `set-tooltalk-message-attribute'.
`make-tooltalk-message' is the preferred way to create and
initialize a message.
- Function: destroy-tooltalk-message MSG
Apply `tt_message_destroy' to the message. It's not necessary to
destroy messages after they've been processed by a message or
pattern callback, the Lisp/ToolTalk callback machinery does this
for you.
File: lispref.info, Node: Receiving Messages, Prev: Sending Messages, Up: ToolTalk Support
Receiving Messages
==================
* Menu:
* Example of Receiving Messages::
* Elisp Interface for Receiving Messages::
File: lispref.info, Node: Example of Receiving Messages, Next: Elisp Interface for Receiving Messages, Up: Receiving Messages
Example of Receiving Messages
-----------------------------
Here's a simple example of a handler for a message that tells XEmacs
to display a string in the mini-buffer area. The message operation is
called `emacs-display-string'. Its first (0th) argument is the string
to display.
(defun tooltalk-display-string-handler (msg)
(message (get-tooltalk-message-attribute msg 'arg_val 0)))
(defvar display-string-pattern
'(category TT_HANDLE
scope TT_SESSION
op "emacs-display-string"
callback tooltalk-display-string-handler))
(let ((p (make-tooltalk-pattern display-string-pattern)))
(register-tooltalk-pattern p))
File: lispref.info, Node: Elisp Interface for Receiving Messages, Prev: Example of Receiving Messages, Up: Receiving Messages
Elisp Interface for Receiving Messages
--------------------------------------
- Function: make-tooltalk-pattern ATTRIBUTES
Create a ToolTalk pattern and initialize its attributes. The
value of attributes must be a list of alternating keyword/values,
where keywords are symbols that name valid pattern attributes or
lists of valid attributes. For example:
(make-tooltalk-pattern
'(category TT_OBSERVE
scope TT_SESSION
op ("operation1" "operation2")
args ("arg1" 12345 (TT_INOUT "arg3" "string"))))
Attribute names are the same as those supported by
`add-tooltalk-pattern-attribute', plus `'args'.
Values must always be strings, integers, or symbols that represent
ToolTalk constants or lists of same. When a list of values is
provided all of the list elements are added to the attribute. In
the example above, messages whose `op' attribute is `"operation1"'
or `"operation2"' would match the pattern.
The value of ARGS should be a list of pattern arguments where each
pattern argument has the following form:
`(mode [value [type]])' or just `value'
Where MODE is one of `TT_IN', `TT_OUT', or `TT_INOUT' and TYPE is
a string. If TYPE isn't specified then `int' is used if VALUE is
a number; otherwise `string' is used. If TYPE is `string' then
VALUE is converted to a string (if it isn't a string already) with
`prin1-to-string'. If only a value is specified then MODE
defaults to `TT_IN'. If MODE is `TT_OUT' then VALUE and TYPE
don't need to be specified. You can find out more about the
semantics and uses of ToolTalk pattern arguments in chapter 3 of
the `ToolTalk Programmer's Guide'.
- Function: register-tooltalk-pattern PAT
XEmacs will begin receiving messages that match this pattern.
- Function: unregister-tooltalk-pattern PAT
XEmacs will stop receiving messages that match this pattern.
- Function: add-tooltalk-pattern-attribute VALUE PAT INDICATOR
Add one value to the indicated pattern attribute. The names of
attributes are the same as the ToolTalk accessors used to set them
less the `tooltalk_pattern_' prefix and the `_add' suffix. For
example, the name of the attribute for the
`tt_pattern_disposition_add' attribute is `disposition'. The
`category' attribute is handled specially, since a pattern can only
be a member of one category (`TT_OBSERVE' or `TT_HANDLE').
Callbacks are handled slightly differently than in the C ToolTalk
API. The value of CALLBACK should be the name of a function of one
argument. It will be called each time the pattern matches an
incoming message.
- Function: add-tooltalk-pattern-arg PAT MODE TYPE VALUE
Add one fully-specified argument to a ToolTalk pattern. MODE must
be one of `TT_IN', `TT_INOUT', or `TT_OUT'. TYPE must be a
string. VALUE can be an integer, string or `nil'. If VALUE is an
integer then an integer argument (`tt_pattern_iarg_add') is added;
otherwise a string argument is added. At present there's no way
to add a binary data argument.
- Function: create-tooltalk-pattern
Create a new ToolTalk pattern and initialize its session attribute
to be the default session.
- Function: destroy-tooltalk-pattern PAT
Apply `tt_pattern_destroy' to the pattern. This effectively
unregisters the pattern.
- Function: describe-tooltalk-message MSG &optional STREAM
Print the message's attributes and arguments to STREAM. This is
often useful for debugging.
File: lispref.info, Node: Internationalization, Next: Tips, Prev: ToolTalk Support, Up: Top
Internationalization
********************
* Menu:
* I18N Levels 1 and 2::
* I18N Level 3::
* I18N Level 4::
File: lispref.info, Node: I18N Levels 1 and 2, Next: I18N Level 3, Up: Internationalization
I18N Levels 1 and 2
===================
XEmacs is now compliant with I18N levels 1 and 2. Specifically,
this means that it is 8-bit clean and correctly handles time and date
functions. XEmacs will correctly display the entire ISO-Latin 1
character set.
The compose key may now be used to create any character in the
ISO-Latin 1 character set not directly available via the keyboard.. In
order for the compose key to work it is necessary to load the file
`x-compose.el'. At any time while composing a character, `C-h' will
display all valid completions and the character which would be produced.