speechd-el

This manual is for speechd-el, 2.7.

Copyright © 2003, 2004, 2005, 2006, 2007, 2008, 2010 Brailcom, o.p.s. Copyright © 2012, 2013 Milan Zamazal

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts and no Back-Cover Texts. A copy of the license is included in the section entitled “GNU Free Documentation License.”

You can also (at your option) distribute this manual under the GNU General Public License:

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.

A copy of the license is included in the section entitled “GNU General Public License”.

1. Introduction

speechd-el is an Emacs client to speech synthesizers, Braille displays and other alternative output interfaces. It provides full speech and Braille output environment for Emacs.

It is aimed primarily at visually impaired users who need non-visual communication with Emacs, but it can be used by anybody who needs sophisticated speech or other kind of alternative output from Emacs. speechd-el can make Emacs a completely speech and BRLTTY enabled application suitable for visually impaired users or, depending on its configuration, it can only speak in certain situations or when asked, to serve needs of any Emacs user.

Programming interfaces are available both to the user interface and for communication with the output devices.

This manual describes the speech/Braille output user interface, how to customize and extend the interface, and the Emacs Lisp libraries. Some degree of familiarity with Speech Dispatcher or BRLTTY on the user level is recommended, although not absolutely necessary.

1.1 Design Goals

speechd-el was designed considering our experience with other free accessibility technologies. We sometimes meet problems such as lack of maintenance power, duplicated efforts, making technology specific solutions instead of generally useful tools, important bugs. As other Free(b)soft projects speechd-el attempts to fill in an empty space in the accessibility area, in a way oriented towards future. speechd-el tries to offer technology that is useful, simple, supporting general accessibility architecture models and that effectively utilizes the limited accessibility development resources.

The particular speechd-el design goals are:

• Providing advanced accessible user environment that works out of the box and utilizes standard Emacs features wherever possible. Emacs accessibility should work as much as possible on the general level without necessity to implement direct support for particular Emacs packages. speechd-el should also preferrably use standard Emacs features if possible instead of implementing its own solutions.
• Implementing just the necessary functionality, without duplicating features presented in other components such as Speech Dispatcher, speech synthesizers or Braille APIs. Emacs accessibility solutions should share features, configuration, code, etc. with other applications to the highest possible extent in order to make life of both users and developers easier.
• Simple and clean source code that requires only minimum maintenance and allows future extensions.
• As little modifications to standard Emacs environment as possible, with the possibility to make additional customizations if needed, either shared or private. Emacs should work the same way whether it speaks or not. Of course optional customizations can be made and the generally useful ones should be included as optional parts of the distribution.
• Ability to work well in a multilingual environment.
• Completely Free Software architecture, without requiring any proprietary component.

1.2 Feature List

Major speechd-el features are:

• Speech output.
• Braille display output and input, mostly identical to the speech output.
• Both automated and explicit reading. You can let Emacs read everything and/or you can ask it to read some parts of the text (such as current line, current buffer, last message, etc.).
• Message priorities ensuring you don’t miss important messages while you needn’t listen to or view unimportant messages.
• “Intelligent” and customizable selection of text to be read based on lines, text properties, buffer contents changes and other criteria.
• Support for changing speech parameters (such as language, voice, rate, pitch, volume, speech synthesizer). Different speech parameters can be used in different buffers, major modes, faces, etc.
• Support for events (such as sound icons).
• Emacs status changes reporting (such as mode, keyboard, process changes, etc.).
• Multilingual environment support. speechd-el works well with languages other than English and offers support for current language selection based on the kind of texts, selected keyboard, etc.
• Reasonable immediate speech and Braille output in most Emacs packages.
• No significant changes of the standard Emacs behavior.
• Speech and Braille output can be enabled/disabled independently to each other and they can be enabled/disabled for the whole Emacs session or just for particular buffers.
• Speech synthesizer independence, you can use all speech synthesizers supported by Speech Dispatcher (such as Festival, Flite, eSpeak, Epos, Dectalk, IBM TTS, Cicero, etc.) and you can use multiple speech synthesizers inside a single Emacs session.
• Braille displays are handled through BRLTTY drivers and APIs.
• Programming libraries for those who want to extend speechd-el facilities or who just want to talk to speech synthesizers, Braille display or other output/input devices.
• Special features for speechd-el developers such as silence in debugger, debugging variables, possibility to disable speechd-el hooks, etc.
• Small code size.

See speechd-el web page if you are interested in comparison with Emacspeak.

1.3 Components

speechd-el design is strictly modular. It contains several components layered each on top of other. Lower layer functions can be used independently of higher level features.

The lowest level components are access libraries to output devices, especially to SSIP (the Speech Dispatcher TCP communication protocol for speech output) and BrlAPI (interface to BRLTTY drivers for communication with Braille displays). They can be used to talk to the output devices directly from Elisp programs.

The next level implements common access to all the devices. Instead of talking to each device independently one can use this layer to output device independent messages that are processed and sent to the output devices as defined in the user configuration. This is the preferred way of communication with the output devices.

On the highest level there is the user interface frontend that makes Emacs read texts and events automatically, defines the corresponding minor modes, key bindings and most of the interactive commands.

There are some other auxiliary components, look into speechd-el source code if interested.

2. speechd-el User Manual

speechd-el allows you to use Emacs without looking at screen, with speech or Braille output only. The main usage area is by blind and visually impaired people, but generally you can use at least the speech output for many purposes, according to your wishes and needs.

You can download the latest released version of speechd-el from http://www.freebsoft.org/pub/projects/speechd-el/.

speechd-el uses Speech Dispatcher for the speech output, so working Speech Dispatcher installation is necessary to produce any speech output. Please look at http://www.freebsoft.org/speechd for more information about Speech Dispatcher.

For the Braille output BRLTTY is used through its BrlAPI interface. To make the Braille output work, BRLTTY must be running and properly configured. Please look at http://www.mielke.cc/brltty/ for more information about BRLTTY.

2.1 Installation

speechd-el installation consists of the following steps:

1. If you use Emacs older than 23.2 then install the ‘eieio’ Elisp library, available from http://cedet.sourceforge.net/eieio.shtml or perhaps your favorite operating system distribution.
2. Copy the speechd-el ‘*.el’ files contained in the distribution package somewhere to your Emacs load path.
3. If you like, byte compile the ‘*.el’ files. Byte compilation is recommended, because it speeds up speechd-el significantly. You can byte compile the ‘*.el’ files using the command

   make compile

   Then install the compiled files to an Emacs load path location as well.

4. Install the ‘speechd-log-extractor’ somewhere to your shell PATH, e.g. ‘/usr/local/bin/’. Installing this script is optional, it is used only for bug reporting.
5. Add the following line to your ‘~/.emacs’:

   (autoload 'speechd-speak "speechd-speak" nil t)

To receive speech output, Speech Dispatcher must be installed and running. Speech Dispatcher version 0.5 or higher is recommended.

To receive Braille output, BRLTTY must be installed and running. BRLTTY version 3.7 or higher is required.

2.2 Starting Speech and Braille Output

After installation of the ‘*.el’ files and restarting Emacs, you can set up speechd-speak using the M-x speechd-speak command. If you want to happen it automatically each time Emacs is started, put the following line to your ‘~/.emacs’ after the autoload line:

(speechd-speak)

M-x speechd-speak

Set up Emacs for alternative output and start speaking or communicating with the Braille display.

Please don’t forget Speech Dispatcher must be running in order to get any speech output and BRLTTY must be running in order to get Braille output!

After the initial setup, the command can be used again to restart the speech or Braille output when needed. Especially, you must run it again if Speech Dispatcher or BRLTTY gets restarted.

After the first invocation, the command is available under the C-e C-s key.

Once the setup is done, enabling and disabling the alternative output is controlled by the speechd-speak and global-speechd-speak minor modes. Usually the mode commands are not used directly, you use the speechd-speak-toggle-speaking command (see section Control Commands), but if you need them, they are available.

M-x speechd-speak-mode

Enable or disable speaking and Braille output in the current buffer. With no argument, this command toggles the mode. Non-null prefix argument turns on the mode. Null prefix argument turns off the mode.

M-x global-speechd-speak-mode

Enable or disable alternative output globally. With no argument, this command toggles the mode. With prefix argument, turn alternative output on if and only if the argument is positive.

2.3 Commands

The basic speechd-el commands are all accessible through a common special prefix key, which is C-e by default (you can change it, see section Customization). If this prefix conflicts with a global Emacs command, the original command is available by double pressing the prefix key. For instance, with the default prefix, the end-of-line command, normally available under the C-e key, can be invoked as C-e C-e.

In the following subsections we use the term reading to indicate any kind of output enabled in speechd-el (such as speaking or Braille output).

2.3.1 Reading Commands

C-e l

Read current line (speechd-speak-read-line). With the prefix argument, read the line only from the current cursor position to the end of line.

C-e b

Read current buffer (speechd-speak-read-buffer).

C-e >

Read current buffer from the cursor to the buffer end (speechd-speak-read-rest-of-buffer).

C-e o

Read buffer of the other window, if any is present (speechd-speak-read-other-window).

C-e r

Read current region (speechd-speak-read-region).

C-e C-r

Read text in the rectangle-region (speechd-speak-read-rectangle).

C-e w

Read the next word after cursor (speechd-speak-read-word).

C-e .

Read current sentence (speechd-speak-read-sentence).

C-e {

Read the next paragraph after cursor (speechd-speak-read-paragraph).

C-e [

Read the next page after cursor (speechd-speak-read-page).

C-e '

Read the next symbolic expression after cursor (speechd-speak-read-sexp).

C-e c

Read the character at the cursor position (speechd-speak-read-char).

C-e C-n

Read the next line (speechd-speak-read-next-line).

C-e C-p

Read the previous line (speechd-speak-read-previous-line).

C-e m

Read last seen Emacs message (speechd-speak-last-message).

C-e RET

Read the mode line (speechd-speak-read-mode-line). Note: This command works only in Emacs 22 or higher.

C-e i

Read last output buffer insertions (speechd-speak-last-insertions). That is the text read in auto-reading buffers, see See section Auto-Reading Buffers.

A few Emacs commands get you stuck in a character reading prompt, a typical example is ispell-word. If you miss what was read before you are prompted for action, you can use the following keystrokes at the prompt to repeat the output texts:

C-e

The same as the C-e m command above (speechd-speak-last-message).

C-a

The same as the C-e i command above (speechd-speak-last-insertions).

If you don’t like such character reading prompt behavior, you can disable it using the following variable:

speechd-speak-allow-prompt-commands

If non-nil, allow the speechd-speak commands mentioned above in read-char prompts.

2.3.2 Informatory Commands

C-e C-i b

Read information about current buffer (speechd-speak-buffer-info).

C-e C-i f

Read information about current frame (speechd-speak-frame-info).

C-e C-i h

Read contents of the header line (speechd-speak-header-line-info). Note: This command works only in Emacs 22 or higher.

C-e C-i m

Read information about current major and minor modes (speechd-speak-mode-info).

C-e C-i c

Read information about current coding systems (speechd-speak-coding-info).

C-e C-i i

Read information about current input method (speechd-speak-input-method-info).

C-e C-i p

Read status of the process associated with the current buffer (speechd-speak-process-info).

2.3.3 Control Commands

C-e q

Toggle reading globally (speechd-speak-toggle-speaking). With a prefix argument, toggle it in the current buffer only.

C-e s

Stop reading current message (speechd-stop). Other queued messages will still be read. If the prefix argument is given, stop reading the current message of any client, not just of the current connection.

C-e x

Stop reading all the queued messages of the current connection and of the connections listed in speechd-cancelable-connections. If the universal prefix argument is given, stop reading all the messages of all connections. If a numeric prefix argument is given, stop all the messages of the current Emacs session.

C-e p

Pause reading — just be quiet for now and postpone current reading until the resume command is invoked (speechd-pause). If the prefix argument is given, pause reading of all clients.

C-e SPC

Resume paused reading (speechd-resume). If the prefix argument is given, resume reading of all clients.

C-e 1

C-e 2

C-e 3

C-e 4

C-e 5

C-e 6

C-e 7

C-e 8

C-e 9

Set one of the predefined speech rates (speechd-speak-key-set-predefined-rate). C-e 1 sets the slowest rate, C-e 5 sets the medium rate, and C-e 9 sets the fastest rate.

2.3.4 Parameter Setting Commands

These commands set various properties of the speech output. They all apply on the current Speech Dispatcher connection (for more information about Speech Dispatcher connections, see section Connection Voices), unless there are invoked with a prefix argument. With a numeric prefix argument they apply on all speechd-el connections, with a universal prefix argument they apply on all Speech Dispatcher connections.

Commands affecting basic parameters of the text-to-speech process:

C-e d l

Set default language of the connection. Specify it as an RFC 1766 language code (e.g. en, cs, etc.).

C-e d .

Specify how to handle punctuation, whether to read it or ignore it. all mode reads all punctuation characters, none mode skips them all quietly, and some mode reads a selected subset of punctuation characters specified in the Speech Dispatcher configuration.

C-e d c

Set capital letter indication mode. icon means signal them with a sound icon, spell means spell them using a special spelling table, and none means no indication.

Commands affecting speech output properties:

C-e d v

Set default voice to be used by the synthesizer (speechd-set-voice). You may select one from the voice set offered by your Speech Dispatcher installation.

C-e d C-v

Set default voice to be used by the synthesizer directly by its synthesizer dependent name (speechd-set-synthesizer-voice). You may select one from the voice set offered by the currently selected Speech Dispatcher output module. This works only with Speech Dispatcher 0.6.3 or higher and not all Speech Dispatcher output modules support this function.

C-e d r

Set exact speech rate, ranging from -100 (slowest) to 100 (fastest) (speechd-set-rate). Most often you will probably want to use the speechd-speak-key-set-predefined-rate command bound to C-e number instead, see Control Commands.

C-e d p

Set voice pitch, ranging from -100 (lowest) to 100 (highest) (speechd-set-pitch).

C-e d V

Set voice volume, ranging from -100 (lowest) to 100 (highest) (speechd-set-volume).

Commands affecting the speech synthesizer:

C-e d o

Switch Speech Dispatcher to the given output module (speechd-set-output-module). Give the module name when you are prompted for the argument.

2.3.5 Spelling

There are two ways to use spelling in speechd-el. The first one is the speechd-speak-spell-mode, which is a minor mode that you can enable for a buffer. The mode is useful if you want to spell more of the buffer contents.

The second spelling method is using the following command:

C-e C-l

Cause the following command to spell the text it reads (speechd-speak-spell). For instance, if you want to spell the word after the cursor, you can type C-e C-l C-e w.

2.3.6 Other Commands

In case Emacs gets completely crazy and refuses to run commands including C-x C-c because of a bug in speechd-el or in an alternative output related custom definition, you can try to invoke the following command as the last resort:

C-e C-x

Try to disable all modes, hooks and wrappers installed by speechd-speak (speechd-unspeak).

The following commands are rarely used, mostly for diagnosing purposes:

C-e z

Repeat the last output text (speechd-repeat).

M-x speechd-say-text

Prompt for a text and read it.

2.4 Customization

All the customization options described below are accessible in the customization group ‘speechd-el’ and its subgroups.

2.4.1 Selecting Drivers

By default speechd-el speaks to ssip and brltty drivers. You can change the set of active drivers by customizing the following variable:

speechd-out-active-drivers

List of names of active output drivers.

If a driver that does not work is present in the variable (e.g. the list contains the brltty symbol while BRLTTY is not actually running), you receive an error message. To prevent the error message, remove the driver from this variable.

When you want to enable or disable some driver temporarily, you can use the following commands:

M-x speechd-out-enable-driver

Enable the given output driver.

M-x speechd-out-disable-driver

Disable the given output driver.

2.4.2 Speech Dispatcher Connection Configuration

Connection configuration variables allow you connect to Speech Dispatcher or BRLTTY running on a remote host or a non-default port and to specify other TCP connection parameters.

Speech Dispatcher connection options:

speechd-connection-method

Connection method to Speech Dispatcher. Possible values are symbols unix-socket for Unix domain sockets and inet-socket for Internet sockets on a given host and port.

speechd-host

Name of the host running Speech Dispatcher to connect to, given as a string. Default is either the contents of the shell variable SPEECHD_HOST variable if set, or "localhost". Value of this variable matters only when Internet sockets are used for communication with Speech Dispatcher.

speechd-port

Port number to connect to. Default is either the contents of the shell variable SPEECHD_PORT if set, or the default Speech Dispatcher port. Value of this variable matters only when Internet sockets are used for communication with Speech Dispatcher.

speechd-autospawn

If non-nil, Emacs will attempt to automatically start Speech Dispatcher. This means that if speechd-el gets a speech request and the Speech Dispatcher server is not running already, speechd-el will launch it.

speechd-timeout

Maximum number of seconds to wait for a Speech Dispatcher answer. If it is exceeded, speechd-el closes the connection. Normally, Speech Dispatcher should answer protocol commands immediately, but if you talk to a Speech Dispatcher in a strange way through a lagging network, you may want to increase the limit.

speechd-spdsend

If non-nil, it is a string naming the spdsend binary (normally "spdsend") to use for communication with Speech Dispatcher. If nil or if you use Emacs 22 or higher, spdsend is not used.

Usually you shouldn’t care about this variable.

BRLTTY connection options:

brltty-default-host

Name of the host running BRLTTY to connect to, given as a string. Default is "localhost".

brltty-default-port

Port number to connect to. It can be either a single number or a list of numbers; in the latter case the given port numbers are attempted in the order they are given until Emacs connects to something. Default is the list of the standard BrlAPI ports.

brltty-authentication-file

File containing the BrlAPI authentication key. It is important to set the variable properly, otherwise the connection to BRLTTY gets rejected. Default is "/etc/brlapi.key".

brltty-coding

Coding in which texts should be sent to BRLTTY. Default is iso-8859-1; if you use non-Western language, you may need to change it to display its characters correctly on the Braille display.

brltty-tty

Number of the Linux console on which speechd-el runs. If this value is not set correctly, speechd-el may not interact well with other applications communicating with BRLTTY. speechd-el tries to find the correct value itself, if this doesn’t work, set this variable properly or set the CONTROLVT environment variable.

brltty-timeout

Maximum number of seconds to wait for a BRLTTY answer. If it is exceeded, speechd-el closes the connection. Normally, BRLTTY should answer protocol commands immediately, but if you talk to BrlAPI in a strange way through a lagging network, you may want to increase the limit.

2.4.3 Default Priorities

If a speechd-el function sends a message to the output device without an explicitly specified priority, the priorities defined by the following variables are used. By changing the values, you can achieve interesting effects. For instance, changing the value of speechd-default-key-priority from notification to message makes all typed characters to be echoed and makes them to interrupt common text reading.

The valid values of all the variables here are: important, message, text, notification, progress. They correspond to Speech Dispatcher priorities, see the Speech Dispatcher manual for more details.

speechd-default-text-priority

Default priority of most text messages.

speechd-default-sound-priority

Default priority of sound icons.

speechd-default-char-priority

Default priority of spelled characters.

speechd-default-key-priority

Default priority of typed keys.

2.4.4 Basic Customization of Speaking

speechd-speak-echo

Symbol determining how to read typed characters. It can have one of the following values:

character

Read characters when they are typed.

word

Read only whole words once they are written.

nil

Don’t echo anything on typing.

speechd-speak-deleted-char

Defines which character to speak when deleting a character. If non-nil, speak the deleted character, otherwise speak the adjacent character.

speechd-speak-buffer-name

When you switch to another buffer and this variable is non-nil, read the new buffer name. If the variable value is the symbol text, read the text from the cursor position to the end of line in the new buffer as well. If the variable is nil, read the text without speaking the buffer name.

speechd-speak-whole-line

If non-nil, read whole line on movement by default. Otherwise read from the point to the end of line on movement by default.

speechd-speak-on-minibuffer-exit

When this variable is non-nil, speechd-el reads the text around cursor after exiting from minibuffer or its recursive level if there is nothing else to read.

speechd-speak-read-command-keys

This variable defines in which situations command keys should be read when their command is performed. If t, the command keys are always read. If nil, they are never read. If list, it may contain one or more of the following symbols describing the situations in which the keys should be read:

movement

Read the command keys if the cursor has moved, no buffer modification happened.

modification

Buffer was modified, the cursor hasn’t moved.

movement-modification

Buffer was modified and the cursor was moved.

If the variable value is t, the command keys are read before the command is performed. Otherwise, their reading is delayed after the command is executed, since the buffer changes and cursor movement must be detected first.

speechd-speak-ignore-command-keys

List of commands that should never echo their command keys.

speechd-speak-read-command-name

If non-nil, read the command name instead of the command keys in the situations defined by the variable speechd-speak-read-command-keys.

speechd-speak-message-time-interval

Minimum time in seconds, after which the same message may be repeated. If the message is the same as the last one, it is not spoken unless the number of seconds defined here has passed from the last spoken message.

2.4.5 Auto-Reading Buffers

It sometimes useful to start reading some buffers without user’s explicit request. For instance, if a help command is invoked, the user usually wants to read the help text immediately. The following variables contain lists of names of the buffers that may be read automatically if they get changed by the last command and are visible in some window of the current frame.

speechd-speak-auto-speak-buffers

Content of these buffers is read after the command on the above conditions if nothing else (e.g. text around a new cursor position) is to be read.

speechd-speak-force-auto-speak-buffers

Like speechd-speak-auto-speak-buffers except that the buffer content is read forcibly, even when something else could be read.

The following variables define how to handle texts inserted during performing user commands. Only newly inserted text is read, the options don’t affect processing of deleted text. Also, the options don’t affect insertions within commands processed in a special way by speechd-el or user definitions, like self-insert-command.

speechd-speak-buffer-insertions

Defines whether insertions in the current buffer should be read automatically. The value may be one of the following symbols:

nil

Don’t read the inserted texts.

t

Read all the inserted texts.

one-line

Read only the first lines of inserted texts.

whole-buffer

Read whole buffer if it was modified in any way.

speechd-speak-insertions-in-buffers

List of names of buffers, in which insertions are automatically read, whether the buffer is current or not and regardless the speechd-speak-buffer-insertions variable.

speechd-speak-priority-insertions-in-buffers

List of names of buffers, in which insertions are automatically read immediately as they appear, not only after a command is evaluated as with speechd-speak-insertions-in-buffers. This is typically useful in comint buffers.

speechd-speak-align-buffer-insertions

If non-nil, the insertion text to be read is extended to the beginning of the first word affected by the insertion. This is particularly useful in completion functions.

If the last command modified the current buffer and moved its cursor to a completely different position, the new cursor position is not indicated in the alternative output. You can change it through the following variable:

speechd-speak-movement-on-insertions

If t, read the text around new cursor position even when the current buffer was modified. If read-only, read it only in read-only buffers. If nil, don’t read it.

2.4.6 Reading State Changes

speechd-el can read information about current Emacs state, like current buffer name, major and minor modes or other buffer attributes, see See section Informatory Commands. Changes in the Emacs state information can be reported automatically, according to the user configuration:

speechd-speak-state-changes

List of identifiers of the Emacs state changes to be automatically reported. The following symbols are recognized as state change identifiers:

buffer-name

buffer-identification

(only in Emacs 22 or higher)

buffer-modified

buffer-read-only

frame-name

frame-identification

(only in Emacs 22 or higher)

header-line

(only in Emacs 22 or higher)

major-mode

minor-modes

buffer-file-coding

terminal-coding

input-method

process

speechd-speak-display-modes

List of minor modes to be read by their display string rather than name. To use the display form of a mode identification may be useful in cases when the display form is more concise than the mode name or when the display form changes without actual change of the mode.

2.4.7 Signalling

Certain situations may be signalled by icons. Icon is typically a short sound or a special indication on a Braille display(1) signalling some event (such as displaying a message, entering prompt, or reaching an empty line). The following variable enables or disables the predefined indications. To learn how to define your own indications, See section Defining Your Own Command Feedbacks.

speechd-speak-signal-events

List of symbols, containing names of events to signal with an icon. The following event names are supported:

start

Start or restart of speechd-el.

empty

Empty text in various situations.

beginning-of-line

Reaching beginning of line after the forward-char and backward-char commands.

end-of-line

Reaching end of line after the forward-char and backward-char commands.

minibuffer

Entering minibuffer.

message

Messages in echo area follow.

2.4.8 Text Properties

By default, after a movement command speechd-el reads the current line. But if the cursor position is surrounded by a text having text properties (typically faces, but any text properties count), speechd-el may read just the piece of the text around the cursor having uniform properties.

Also, if font lock mode is enabled, faces may be mapped to different voices.

speechd-speak-by-properties-on-movement

Method of selection of the piece of text to be read on movement. The variable may take one of the following values.

nil

Text properties are not considered at all.

t

All text properties are considered.

list of faces

Only the named faces are considered.

speechd-speak-by-properties-always

List of commands that always consider text properties, even when the speechd-speak-by-properties-on-movement variable is nil.

speechd-speak-by-properties-never

List of commands that never consider text properties, even when the speechd-speak-by-properties-on-movement variable is non-nil.

speechd-speak-faces

This variable allows you to invoke actions when the cursor ends up on a certain face after a user command is performed. The variable value is an alist with elements of the form (face . action).

If a movement command leaves the cursor on a face and there is no explicit reading bound to the command, action is invoked. If action is a string, that string is read. If action is a function, it is invoked, with no arguments.

speechd-face-voices

Mapping of faces to voices. The variable value is an alist with elements of the form (face . voice) where face is a face and voice is a voice identifier defined in speechd-voices, see Defining voices. Each face is spoken in the corresponding voice. If there’s no item for a given face in this variable, the face is spoken in the current voice.

Note that the mapping takes the effect only if font lock mode is enabled.

2.4.9 Using multiple languages

You can use speechd-el with multiple languages. However, the process can’t be easily automated, since ordinary text does not contain any information about its language. So if you want to use speechd-el with the output being spoken in multiple languages, you must provide speechd-el some hints.

The language settings described below currently apply only to the spoken output, to select the proper voice. They don’t affect the Braille output; but you may want to set language coding for Braille, See section Speech Dispatcher Connection Configuration.

The basic means for providing language information to speechd-el is the variable speechd-language. Each time speechd-el is about to speak a piece of text, it checks the variable for the language code and if it is non-nil, it speaks the text in the corresponding language. The non-nil value must be a string of the RFC 1766 language code (e.g. en, cs, etc.).

Most often you will probably want to set the variable in a particular file, see (emacs)File Variables section ‘File Variables’ in GNU Emacs Manual, or as a buffer local variable, see (emacs)Locals section ‘Locals’ in GNU Emacs Manual, in mode hooks, see (emacs)Hooks section ‘Hooks’ in GNU Emacs Manual.

If a piece of the text has the language property containing the RFC 1766 language code, it is spoken in the corresponding language, regardless of other settings. You can use the speechd-language function to put the property on a string in your Elisp programs.

Another good way of using multiple languages is to use multiple connections for separating language dependent buffers or modes, see Multiple Connections, and to set the language parameter for each such a connection, see Connection Voices.

If nothing helps better, you can select languages according to the current input method:

speechd-speak-input-method-languages

Alist mapping input methods to languages. Each of the alist elements is of the form (input-method-name . language), where input-method-name is a string naming the input method and language is an RFC 1766 language code accepted by SSIP (e.g. en, cs, etc.). If the current input method is present in the alist, the corresponding language is selected unless overridden by another setting.

2.4.10 Defining voices

You can define special voices in speechd-el that can be used in different situations, e.g. to speak different faces in different voices (see section Text Properties) or to set different punctuation modes for different kinds of buffers (see section Multiple Connections). speechd-el voices define not only basic voice characteristics, but also speech characteristics like pitch or rate and special properties like punctuation reading or capital character signalization.

Voice definition is contained in the following variable:

speechd-voices

Alist of voice identifiers and their parameters.

Each element of the list is of the form (voice-id . parameters), where voice-id is a symbol under which the voice will be accessed and parameters is an alist of parameter identifiers and parameter values. Valid parameter names are the following symbols: language, gender, age, style, name, rate, pitch, volume, punctuation-mode, capital-character-mode, message-priority, output-module. Please note that any parameter entry present will change the corresponding parameter, even if the parameter value is nil or empty; if you don’t want to change the parameter in any way by the voice, don’t put it to the list (and don’t enable its entry in customize).

name value is a string identifying Speech Dispatcher voice name. If it is not given, the parameters gender, age, and style are considered to select a Speech Dispatcher voice. gender value can be one of the symbols male, female, neutral. age can be one of the symbols middle-adult, child. neutral. style can be one of the numbers 1, 2, 3 (style values are likely to be changed in future).

The message-priority parameter sets priority of any message of the voice. Its value is any of the message priority symbols.

See the corresponding speechd-set-* functions for valid values of other parameters.

The voice named nil is special, it defines a default voice. Explicit definition of its parameters is optional.

2.4.11 Connection Voices

With the help of the following variable you can let set various connection parameters, like speech rate, language, etc., automatically. speechd-el can open multiple connections according to various criteria (see section Multiple Connections), you can set different parameters to different connections, based on their names.

speechd-connection-voices

Alist of connection names and corresponding voices. Each list element is of the form (connection-name . voice), where connection-name is a connection name given as a string and voice is a voice identifier defined in the variable speechd-voices.

The default voice (named nil) is used for connections that are not present in this variable.

So that changing the value of the variable could take the full effect, the open connections must be reopened. Unless you use the customization interface, you must invoke the C-u M-x speechd-speak command to ensure this.

There is a command to help you with setting connection voice and its parameters:

C-e C-a

Store the current connection parameters to a specified voice in the speechd-voices variable and set that voice for the current connection in the speechd-connection-voices variable.

Please note you are still responsible to save the variables if you want to use them in future sessions.

2.4.12 Multiple Connections

You can arrange speechd-el to use separate connections to Speech Dispatcher for certain buffers or major modes. This is basically useful to allow independent parameter setting for those buffers and major modes, both by hand and through the configuration (see section Connection Voices).

Each Speech Dispatcher connection has its unique name. By default, speechd-el uses a connection named "default". All you need to create a separate connection is to let speechd-el choose a different connection name in certain situations. The process of connection name selection is driven by the speechd-speak-connections variable.

speechd-speak-connections

Alist mapping major modes and buffers to Speech Dispatcher connections. Each element of the alist is of the form (mode-or-buffer . connection-name).

When speechd-el wants to send a message, it tests the current environment against the mode-or-buffer entries. mode-or-buffer may be one of the following objects, in the order of priority from the highest to the lowest:

• a list, representing a function call that should return a non-nil value if and only if the element should be applied
• regular expression matching desired buffer names
• the symbol :minibuffer, representing minibuffers
• major mode symbol
• nil, representing non-buffer areas, e.g. echo area
• t, representing the default value if nothing else matches

If more entries match in some situation, the entry with the highest priority is used.

connection-name is an arbitrary non-empty string naming the corresponding connection. If no connection with such a name is open in the running speechd-el, it is automatically created when there’s something to send to it.

speechd-cancelable-connections

List of names of connections that are cancelled by default when a cancel function is called.

2.4.13 Keys

The command keys of speechd-el are defined by the speechd-speak-prefix variable and the speechd-speak-mode-map key map.

speechd-speak-prefix

This variable defines the prefix key of the speechd-el commands, which is C-e by default. If you change the variable value after speaking has already been started through the speechd-speak command and you do not set it through the customization interface, you must rerun the speechd-speak so that the change took any effect.

speechd-speak-mode-map

This key map holds the mapping of the keys following the prefix key. You can set keys here in the usual way, e.g.

(define-key speechd-speak-mode-map "t" 'speechd-say-text)

to get the speechd-say-text command bound to the C-e t key (assuming C-e is the prefix key).

2.4.14 Braille Display Keys

When using Braille display output, speechd-el can bind actions to the Braille display keys. The Braille key bindings are defined in the following variables:

speechd-braille-key-functions

Alist of Braille display key codes and corresponding Emacs functions. If the given key is pressed, the corresponding function is called with a speechd-brltty-driver instance as its single argument (read the source code for information about speechd-el output drivers).

The key codes are either integers (for BRLTTY 3.7 and older) or lists containing three integers (for BRLTTY 3.8 and newer). See the default variable value for examples of possible key codes.

The assigned functions needn’t be interactive. Actually as the functions may be invoked by asynchronous events any time at any place, they shouldn’t modify current environment in any inappropriate way. For this reason it is recommended not to assign user commands to the keys here.

‘speechd-brltty.el’ contains some predefined functions that can be assigned to the Braille display keys here:

speechd-brltty-scroll-left

Scroll towards the beginning of the currently displayed message.

speechd-brltty-scroll-right

Scroll towards the end of the currently displayed message.

speechd-brltty-scroll-to-bol

Scroll to the beginning of the currently displayed message.

speechd-brltty-scroll-to-eol

Scroll to the end of the currently displayed message.

speechd-brltty-scroll-to-cursor

Scroll to the cursor position (if any) in the displayed message.

speechd-brltty-finish-message

Stop displaying the current message and display the next one.

speechd-brltty-cancel

Stop displaying the current message and discard all messages waiting in the queue.

speechd-brltty-previous-message

Display the previous message from the history.

speechd-brltty-next-message

Display the next message from the history.

speechd-brltty-first-message

Display the first message in the history.

speechd-brltty-last-message

Display the last message in the history.

Additionally, the following macro is provided:

speechd-brltty-command-key-function key

Insert function for handling key as a general input key. This is useful for handling Braille keys acting as general character input keys.

The speechd-braille-key-functions variable contains some default bindings initially, but as the keys and their codes differ a lot for various Braille displays, you probably need to adjust it for your particular device. You can figure out the display key codes by setting the speechd-braille-show-unknown-keys variable to t and pressing the display keys.

speechd-braille-show-unknown-keys

If non-nil, show codes of the pressed Braille keys that have no function assigned in speechd-braille-key-functions. This is useful to figure out the Braille key codes.

With BrlTTY 3.8 and higher BrlTTY can handle many braille keys itself in X environment. So speechd-el doesn’t try to handle most keys itself by default. Instead it handles only keys assigned in speechd-braille-key-functions. If this is a problem, typically when looking for braille key codes, the following command can be useful:

C-e C-b k

Toggle handling braille keys by speechd-el. If BrlTTY handles the keys (this is the default behavior), speechd-el receives only keys which are assigned to commands in speechd-braille-key-functions. If speechd-el handles the keys, then BrlTTY sends all the pressed keys to speechd-el without processing them itself.

2.4.15 Minor mode hooks

speechd-el provides a minor mode that enables and disables the reading, See section Starting Speech and Braille Output. You can let perform custom actions on entering it through the following hook.

speechd-speak-mode-hook

Hook run when speechd-speak minor mode is enabled.

2.4.16 Debugging speechd-el

When you try to debug speechd-speak functions, you can experience the problem of recursive reading in the Elisp debugger. To avoid it, you can instruct speechd-el to be quiet in Elisp debuggers:

speechd-speak-in-debugger

If nil, speechd-speak functions won’t be reading in Elisp debuggers.

2.5 Defining Your Own Command Feedbacks

Writing your own feedback definitions generally requires knowledge of Elisp programming. But don’t be afraid, you can set basic things without it, just following instructions here.

speechd-el allows you to say a text, output an icon, or call any Elisp expression before or after a command or a function is invoked. There are two macros that allow you to do it, while ensuring everything is set up properly:

speechd-speak-command-feedback command position feedback

Install feedback invocation on command. command is a name of an interactive function (use C-h C-c to get a name of the command bound to a given key).

position may be one of the symbols before and after to call the feedback before or after the command is invoked.

feedback may be a string or any Elisp expression. If it is a string (a text enclosed in double quotes), it defines a text to be spoken or a sound icon to be played. If the string starts with an asterisk (*), it names a sound icon (the asterisk is not a part of the name), otherwise it is a normal text.

Example:

(speechd-speak-command-feedback suspend-emacs before "Suspending Emacs!")

You can put this line of Elisp code to your ‘~/.emacs’ to ensure you are informed when you invoke the suspend-emacs command (usually bound to C-z).

speechd-speak-function-feedback function position feedback

This is the same as speechd-speak-command-feedback, except it is called anytime the given function is invoked, whether interactively or not. Also, function may be any function, not only an interactive command.

Please note:

• Due to Emacs deficiency, the feedback mechanism may not work on built-in functions.
• Be careful if you want to install function feedbacks without help of the macros above. The macros install code ensuring nothing is spoken if speechd-speak-mode is disabled and other similar precautions. If you do not use them, you should make those precautions yourself.

2.6 Problems You May Encounter

• Why are some menu items in Info not read?

  This is due the way how Emacs fontifies the menu items. Try to set the Info-fontify-maximum-menu-size variable to 0 to avoid the problem.

• How to make appointments read their notifications?

  Set the variable appt-msg-window to nil. Also, adding "diary" to the speechd-speak-auto-speak-buffer variable may be useful.

• How to avoid printing URL when moving through links in w3m-el?

  Add the following code to your ‘~/.emacs’:

  (defadvice w3m-print-this-url (around my-w3m-print-this-url activate) (when (eq this-command 'w3m-print-this-url) ad-do-it))

• How to avoid excessive occurrences of TAB (C-i) and NL (C-j) characters on a Braille display in some buffers (e.g. *Completion* buffer)?

  Braille displays generally display exact content, which is usually what you want. But sometimes TAB characters are inserted to Emacs buffers for the sole purpose of visual formatting. You can tell Emacs to suppress this behavior when possible by adding the following code to your ‘~/.emacs’:

  (setq-default indent-tabs-mode nil)

• In some situations, when a modified text is read after performing a command, the text is read in separate pieces and some of the pieces are repeated.

  Buffer modifications can be performed by many different ways in Elisp programs. speechd-el is unable to track them always satisfactory. If you have a reasonable idea how to improve buffer modification reading, please tell us.

  As a workaround, if you encounter this problem when performing some often used commands, you might want to define your own speaking feedbacks of those commands. See section Defining Your Own Command Feedbacks, for more details.

• There are sometimes small delays (about 1 second) before something is read after a command.

  Maybe Emacs is garbage collecting in the meantime. Try to increase the value of the gc-cons-threshold variable, e.g. to 4000000. It may increase or reduce the performance, depending on your environment and particular requirements.

  If you didn’t byte compile the source ‘*.el’ files, do so.

  If you are an experienced Elisp hacker and you can find out why speechd-el produces significant amount of data increasing the frequency of garbage collection and how to make the things better, your help is welcome!

• During holding down the C-n key, the screen gets frozen and the cursor doesn’t move for a while.

  Emacs redisplay routines are generally not invoked when Emacs is busy. speechd-el combined with your autorepeat may achieve such a state quite easily. If that’s a real problem to you, you can reduce your autorepeat rate or buy a faster computer.

  Also, if you didn’t byte compile the source ‘*.el’ files, do so.

  Certainly, any tips increasing speechd-el performance are welcome.

2.7 Useful Emacs tips

Don’t forget that Elisp allows you to define many useful functions. Typically, you may want to define commands reporting some information, which can be easily identified on the Emacs screen, but which is not so easily provided in the standard speech output interface.

Some examples:

• Reporting current date in calendar:

  (defun report-day () (interactive) (message "%s" (calendar-date-string (calendar-cursor-to-date t))))

• Reporting current diary appointments:

  (defun report-current-appointments () (interactive) (let ((appt-now-displayed nil)) (appt-check)))

• Reviewing ispell choices

  When you invoke the ispell-word command and the checked word is mispelled, ispell offers you the list of alternative spellings. You can let speechd-el repeat the list by pressing C-a in the ispell prompt. When you want to review the choices closely, press C-r to enter recursive edit and then switch to the *Choices* window with C-x o. After you review the choices, you can return back to the ispell prompt by pressing C-M-c.

2.8 How to Report speechd-el or Speech Dispatcher Bugs

When you encounter a speechd-el bug, you can report it to us using the following command. Before doing it, please read the whole text of this section to allow handling your bug report in a more efficient way.

M-x speechd-bug

Report a speechd-el or Speech Dispatcher bug. The command asks you for some information and then asks you whether you can reproduce the bug. If you can, answer y and start reproducing the bug immediately. As soon as the bug is reproduced, type C-e C-f. Then you can (and should) further edit the generated mail and send it in the usual way.

M-x speechd-bug-reproduce

Start reproducing a speechd-el or Speech Dispatcher bug. All user and Speech Dispatcher actions are watched from this moment.

Bug reproduction is finished by pressing the C-e C-f keys. After the bug reproduction is finished, information about it is inserted into the buffer where the speechd-bug-reproduce command was invoked.

This command is useful when you want to provide information about a bug without generating new bug report.

When reporting the bugs, please always remember the following instructions:

• Write as much information about the problem as possible. Describe what doesn’t work, what’s the expected behavior, what actions have triggered the bug, what’s special about your Emacs environment or Speech Dispatcher configuration, etc. Don’t try to analyze too much which information is important and which is not — everything may be important to the developers, so try not to forget to mention anything that might be important, better more than less. Missing information may cause the developers won’t be able to handle the bug at all.
• Be as much precise as possible. Don’t expect the developers to know the context or to know the way you typically use Emacs and speechd-el. Write in exact terms — instead of just writing “when I invoke foo” write better “when I press the keys ‘M-x foo RET’, thus invoking the ‘foo’ command”; or instead of writing “doesn’t speak what I expect” write like “speaks ‘blah blah’ instead of ‘bleh bleh bleh’ what is I expect, since ‘bleh bleh bleh’ is the text of the whole line”.
• When reproducing the bug, try to have the Speech Dispatcher logging enabled to the highest level — set the LogLevel option to 5 in your ‘speechd.conf’ configuration file.
• When reproducing the bug, don’t do any extra actions and invoke C-e C-f as soon as the bug is reproduce. Thus you avoid losing the relevant information of the automatically extracted log files in an unnecessary garbage.
• You can also look at the Speech Dispatcher bug reporting instructions, see (speechd)Reporting Bugs section ‘Reporting Bugs’ in Speech Dispatcher.

3. speechd-el Emacs Lisp Library

The speechd-el code can be classified into several parts:

• Low-level libraries for Speech Dispatcher and BrlAPI access implemented in the files ‘speechd.el’ and ‘brltty.el’.
• General device independent output mechanism defined in the ‘speechd-out.el’ file. Its particular device implementations are in the files ‘speechd-ssip.el’ and ‘speechd-brltty.el’.
• User interface implemented in ‘speechd-speak.el’.

You can use the libraries to communicate with Speech Dispatcher, BRLTTY or other devices in your own programs.

Right now, there’s no real programmer’s manual to the libraries. Please read docstrings of available variables, functions and macros.

Nevertheless, here are some instructions you can and should follow:

• Don’t use any functions, variables or other Lisp objects, names of which start with prefixes separated by double dashes (such as speechd-- or speechd-speak--). These objects are considered private and may change incompatibly or disappear at any time without notice.
• If you want to select or create a particular SSIP connection, do so by binding the speechd-client-name variable:

  (let ((speechd-client-name "something")) ... the code using the connection "something" ... )

  Please note it’s usually bad idea to open two concurrent Speech Dispatcher connections sharing the same client name.

• Otherwise there should be no special pitfalls and you should be safe to do anything what makes sense.

You can also look at Defining Your Own Command Feedbacks.

4. Contact Information

If you want to report a bug on speechd-el, send complete information regarding the bug to the bug tracking address speechd-el@bugs.freebsoft.org. If you have a patch to speechd-el, you can send it to the same address.

Please, before sending us any bug report, read the bug reporting instructions, see How to Report speechd-el or Speech Dispatcher Bugs. Thus you allow us to process your bug report more efficiently, resulting in a better response to the report and faster resolving of the issue.

If you have any questions, suggestions, or anything else to tell us, feel free to contact us at the e-mail address speechd@freebsoft.org.

A. Copying Conditions of This Manual

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Version 1.2, November 2002

Copyright © 2000,2001,2002 Free Software Foundation, Inc.
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   12. Preserve all the Invariant Sections of the Document, unaltered in their text and in their titles. Section numbers or the equivalent are not considered part of the section titles.
   13. Delete any section Entitled “Endorsements”. Such a section may not be included in the Modified Version.
   14. Do not retitle any existing section to be Entitled “Endorsements” or to conflict in title with any Invariant Section.
   15. Preserve any Warranty Disclaimers.

   If the Modified Version includes new front-matter sections or appendices that qualify as Secondary Sections and contain no material copied from the Document, you may at your option designate some or all of these sections as invariant. To do this, add their titles to the list of Invariant Sections in the Modified Version’s license notice. These titles must be distinct from any other section titles.

   You may add a section Entitled “Endorsements”, provided it contains nothing but endorsements of your Modified Version by various parties—for example, statements of peer review or that the text has been approved by an organization as the authoritative definition of a standard.

   You may add a passage of up to five words as a Front-Cover Text, and a passage of up to 25 words as a Back-Cover Text, to the end of the list of Cover Texts in the Modified Version. Only one passage of Front-Cover Text and one of Back-Cover Text may be added by (or through arrangements made by) any one entity. If the Document already includes a cover text for the same cover, previously added by you or by arrangement made by the same entity you are acting on behalf of, you may not add another; but you may replace the old one, on explicit permission from the previous publisher that added the old one.

   The author(s) and publisher(s) of the Document do not by this License give permission to use their names for publicity for or to assert or imply endorsement of any Modified Version.

6. COMBINING DOCUMENTS

   You may combine the Document with other documents released under this License, under the terms defined in section 4 above for modified versions, provided that you include in the combination all of the Invariant Sections of all of the original documents, unmodified, and list them all as Invariant Sections of your combined work in its license notice, and that you preserve all their Warranty Disclaimers.

   The combined work need only contain one copy of this License, and multiple identical Invariant Sections may be replaced with a single copy. If there are multiple Invariant Sections with the same name but different contents, make the title of each such section unique by adding at the end of it, in parentheses, the name of the original author or publisher of that section if known, or else a unique number. Make the same adjustment to the section titles in the list of Invariant Sections in the license notice of the combined work.

   In the combination, you must combine any sections Entitled “History” in the various original documents, forming one section Entitled “History”; likewise combine any sections Entitled “Acknowledgements”, and any sections Entitled “Dedications”. You must delete all sections Entitled “Endorsements.”

7. COLLECTIONS OF DOCUMENTS

   You may make a collection consisting of the Document and other documents released under this License, and replace the individual copies of this License in the various documents with a single copy that is included in the collection, provided that you follow the rules of this License for verbatim copying of each of the documents in all other respects.

   You may extract a single document from such a collection, and distribute it individually under this License, provided you insert a copy of this License into the extracted document, and follow this License in all other respects regarding verbatim copying of that document.

8. AGGREGATION WITH INDEPENDENT WORKS

   A compilation of the Document or its derivatives with other separate and independent documents or works, in or on a volume of a storage or distribution medium, is called an “aggregate” if the copyright resulting from the compilation is not used to limit the legal rights of the compilation’s users beyond what the individual works permit. When the Document is included in an aggregate, this License does not apply to the other works in the aggregate which are not themselves derivative works of the Document.

   If the Cover Text requirement of section 3 is applicable to these copies of the Document, then if the Document is less than one half of the entire aggregate, the Document’s Cover Texts may be placed on covers that bracket the Document within the aggregate, or the electronic equivalent of covers if the Document is in electronic form. Otherwise they must appear on printed covers that bracket the whole aggregate.

9. TRANSLATION

   Translation is considered a kind of modification, so you may distribute translations of the Document under the terms of section 4. Replacing Invariant Sections with translations requires special permission from their copyright holders, but you may include translations of some or all Invariant Sections in addition to the original versions of these Invariant Sections. You may include a translation of this License, and all the license notices in the Document, and any Warranty Disclaimers, provided that you also include the original English version of this License and the original versions of those notices and disclaimers. In case of a disagreement between the translation and the original version of this License or a notice or disclaimer, the original version will prevail.

   If a section in the Document is Entitled “Acknowledgements”, “Dedications”, or “History”, the requirement (section 4) to Preserve its Title (section 1) will typically require changing the actual title.

10. TERMINATION

    You may not copy, modify, sublicense, or distribute the Document except as expressly provided for under this License. Any other attempt to copy, modify, sublicense or distribute the Document is void, and will automatically terminate your rights under this License. However, parties who have received copies, or rights, from you under this License will not have their licenses terminated so long as such parties remain in full compliance.

11. FUTURE REVISIONS OF THIS LICENSE

    The Free Software Foundation may publish new, revised versions of the GNU Free Documentation License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. See http://www.gnu.org/copyleft/.

    Each version of the License is given a distinguishing version number. If the Document specifies that a particular numbered version of this License “or any later version” applies to it, you have the option of following the terms and conditions either of that specified version or of any later version that has been published (not as a draft) by the Free Software Foundation. If the Document does not specify a version number of this License, you may choose any version ever published (not as a draft) by the Free Software Foundation.

A.1.1 ADDENDUM: How to use this License for your documents

To use this License in a document you have written, include a copy of the License in the document and put the following copyright and license notices just after the title page:

  Copyright (C)  year  your name.
  Permission is granted to copy, distribute and/or modify this document
  under the terms of the GNU Free Documentation License, Version 1.2
  or any later version published by the Free Software Foundation;
  with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
  A copy of the license is included in the section entitled ``GNU
  Free Documentation License''.

If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts, replace the “with...Texts.” line with this:

    with the Invariant Sections being list their titles, with
    the Front-Cover Texts being list, and with the Back-Cover Texts
    being list.

If you have Invariant Sections without Cover Texts, or some other combination of the three, merge those two alternatives to suit the situation.

If your document contains nontrivial examples of program code, we recommend releasing these examples in parallel under your choice of free software license, such as the GNU General Public License, to permit their use in free software.

A.2 GNU General Public License

Version 3, 29 June 2007

Copyright © 2007 Free Software Foundation, Inc. http://fsf.org/

Everyone is permitted to copy and distribute verbatim copies of this
license document, but changing it is not allowed.

Preamble

The GNU General Public License is a free, copyleft license for software and other kinds of works.

The licenses for most software and other practical works are designed to take away your freedom to share and change the works. By contrast, the GNU General Public License is intended to guarantee your freedom to share and change all versions of a program—to make sure it remains free software for all its users. We, the Free Software Foundation, use the GNU General Public License for most of our software; it applies also to any other work released this way by its authors. You can apply it to your programs, too.

When we speak of free software, we are referring to freedom, not price. Our General Public Licenses are designed to make sure that you have the freedom to distribute copies of free software (and charge for them if you wish), that you receive source code or can get it if you want it, that you can change the software or use pieces of it in new free programs, and that you know you can do these things.

To protect your rights, we need to prevent others from denying you these rights or asking you to surrender the rights. Therefore, you have certain responsibilities if you distribute copies of the software, or if you modify it: responsibilities to respect the freedom of others.

For example, if you distribute copies of such a program, whether gratis or for a fee, you must pass on to the recipients the same freedoms that you received. You must make sure that they, too, receive or can get the source code. And you must show them these terms so they know their rights.

Developers that use the GNU GPL protect your rights with two steps: (1) assert copyright on the software, and (2) offer you this License giving you legal permission to copy, distribute and/or modify it.

For the developers’ and authors’ protection, the GPL clearly explains that there is no warranty for this free software. For both users’ and authors’ sake, the GPL requires that modified versions be marked as changed, so that their problems will not be attributed erroneously to authors of previous versions.

Some devices are designed to deny users access to install or run modified versions of the software inside them, although the manufacturer can do so. This is fundamentally incompatible with the aim of protecting users’ freedom to change the software. The systematic pattern of such abuse occurs in the area of products for individuals to use, which is precisely where it is most unacceptable. Therefore, we have designed this version of the GPL to prohibit the practice for those products. If such problems arise substantially in other domains, we stand ready to extend this provision to those domains in future versions of the GPL, as needed to protect the freedom of users.

Finally, every program is threatened constantly by software patents. States should not allow patents to restrict development and use of software on general-purpose computers, but in those that do, we wish to avoid the special danger that patents applied to a free program could make it effectively proprietary. To prevent this, the GPL assures that patents cannot be used to render the program non-free.

The precise terms and conditions for copying, distribution and modification follow.

TERMS AND CONDITIONS

1. Definitions.

   “This License” refers to version 3 of the GNU General Public License.

   “Copyright” also means copyright-like laws that apply to other kinds of works, such as semiconductor masks.

   “The Program” refers to any copyrightable work licensed under this License. Each licensee is addressed as “you”. “Licensees” and “recipients” may be individuals or organizations.

   To “modify” a work means to copy from or adapt all or part of the work in a fashion requiring copyright permission, other than the making of an exact copy. The resulting work is called a “modified version” of the earlier work or a work “based on” the earlier work.

   A “covered work” means either the unmodified Program or a work based on the Program.

   To “propagate” a work means to do anything with it that, without permission, would make you directly or secondarily liable for infringement under applicable copyright law, except executing it on a computer or modifying a private copy. Propagation includes copying, distribution (with or without modification), making available to the public, and in some countries other activities as well.

   To “convey” a work means any kind of propagation that enables other parties to make or receive copies. Mere interaction with a user through a computer network, with no transfer of a copy, is not conveying.

   An interactive user interface displays “Appropriate Legal Notices” to the extent that it includes a convenient and prominently visible feature that (1) displays an appropriate copyright notice, and (2) tells the user that there is no warranty for the work (except to the extent that warranties are provided), that licensees may convey the work under this License, and how to view a copy of this License. If the interface presents a list of user commands or options, such as a menu, a prominent item in the list meets this criterion.

2. Source Code.

   The “source code” for a work means the preferred form of the work for making modifications to it. “Object code” means any non-source form of a work.

   A “Standard Interface” means an interface that either is an official standard defined by a recognized standards body, or, in the case of interfaces specified for a particular programming language, one that is widely used among developers working in that language.

   The “System Libraries” of an executable work include anything, other than the work as a whole, that (a) is included in the normal form of packaging a Major Component, but which is not part of that Major Component, and (b) serves only to enable use of the work with that Major Component, or to implement a Standard Interface for which an implementation is available to the public in source code form. A “Major Component”, in this context, means a major essential component (kernel, window system, and so on) of the specific operating system (if any) on which the executable work runs, or a compiler used to produce the work, or an object code interpreter used to run it.

   The “Corresponding Source” for a work in object code form means all the source code needed to generate, install, and (for an executable work) run the object code and to modify the work, including scripts to control those activities. However, it does not include the work’s System Libraries, or general-purpose tools or generally available free programs which are used unmodified in performing those activities but which are not part of the work. For example, Corresponding Source includes interface definition files associated with source files for the work, and the source code for shared libraries and dynamically linked subprograms that the work is specifically designed to require, such as by intimate data communication or control flow between those subprograms and other parts of the work.

   The Corresponding Source need not include anything that users can regenerate automatically from other parts of the Corresponding Source.

   The Corresponding Source for a work in source code form is that same work.

3. Basic Permissions.

   All rights granted under this License are granted for the term of copyright on the Program, and are irrevocable provided the stated conditions are met. This License explicitly affirms your unlimited permission to run the unmodified Program. The output from running a covered work is covered by this License only if the output, given its content, constitutes a covered work. This License acknowledges your rights of fair use or other equivalent, as provided by copyright law.

   You may make, run and propagate covered works that you do not convey, without conditions so long as your license otherwise remains in force. You may convey covered works to others for the sole purpose of having them make modifications exclusively for you, or provide you with facilities for running those works, provided that you comply with the terms of this License in conveying all material for which you do not control copyright. Those thus making or running the covered works for you must do so exclusively on your behalf, under your direction and control, on terms that prohibit them from making any copies of your copyrighted material outside their relationship with you.

   Conveying under any other circumstances is permitted solely under the conditions stated below. Sublicensing is not allowed; section 10 makes it unnecessary.

4. Protecting Users’ Legal Rights From Anti-Circumvention Law.

   No covered work shall be deemed part of an effective technological measure under any applicable law fulfilling obligations under article 11 of the WIPO copyright treaty adopted on 20 December 1996, or similar laws prohibiting or restricting circumvention of such measures.

   When you convey a covered work, you waive any legal power to forbid circumvention of technological measures to the extent such circumvention is effected by exercising rights under this License with respect to the covered work, and you disclaim any intention to limit operation or modification of the work as a means of enforcing, against the work’s users, your or third parties’ legal rights to forbid circumvention of technological measures.

5. Conveying Verbatim Copies.

   You may convey verbatim copies of the Program’s source code as you receive it, in any medium, provided that you conspicuously and appropriately publish on each copy an appropriate copyright notice; keep intact all notices stating that this License and any non-permissive terms added in accord with section 7 apply to the code; keep intact all notices of the absence of any warranty; and give all recipients a copy of this License along with the Program.

   You may charge any price or no price for each copy that you convey, and you may offer support or warranty protection for a fee.

6. Conveying Modified Source Versions.

   You may convey a work based on the Program, or the modifications to produce it from the Program, in the form of source code under the terms of section 4, provided that you also meet all of these conditions:

   1. The work must carry prominent notices stating that you modified it, and giving a relevant date.
   2. The work must carry prominent notices stating that it is released under this License and any conditions added under section 7. This requirement modifies the requirement in section 4 to “keep intact all notices”.
   3. You must license the entire work, as a whole, under this License to anyone who comes into possession of a copy. This License will therefore apply, along with any applicable section 7 additional terms, to the whole of the work, and all its parts, regardless of how they are packaged. This License gives no permission to license the work in any other way, but it does not invalidate such permission if you have separately received it.
   4. If the work has interactive user interfaces, each must display Appropriate Legal Notices; however, if the Program has interactive interfaces that do not display Appropriate Legal Notices, your work need not make them do so.

   A compilation of a covered work with other separate and independent works, which are not by their nature extensions of the covered work, and which are not combined with it such as to form a larger program, in or on a volume of a storage or distribution medium, is called an “aggregate” if the compilation and its resulting copyright are not used to limit the access or legal rights of the compilation’s users beyond what the individual works permit. Inclusion of a covered work in an aggregate does not cause this License to apply to the other parts of the aggregate.

7. Conveying Non-Source Forms.

   You may convey a covered work in object code form under the terms of sections 4 and 5, provided that you also convey the machine-readable Corresponding Source under the terms of this License, in one of these ways:

   1. Convey the object code in, or embodied in, a physical product (including a physical distribution medium), accompanied by the Corresponding Source fixed on a durable physical medium customarily used for software interchange.
   2. Convey the object code in, or embodied in, a physical product (including a physical distribution medium), accompanied by a written offer, valid for at least three years and valid for as long as you offer spare parts or customer support for that product model, to give anyone who possesses the object code either (1) a copy of the Corresponding Source for all the software in the product that is covered by this License, on a durable physical medium customarily used for software interchange, for a price no more than your reasonable cost of physically performing this conveying of source, or (2) access to copy the Corresponding Source from a network server at no charge.
   3. Convey individual copies of the object code with a copy of the written offer to provide the Corresponding Source. This alternative is allowed only occasionally and noncommercially, and only if you received the object code with such an offer, in accord with subsection 6b.
   4. Convey the object code by offering access from a designated place (gratis or for a charge), and offer equivalent access to the Corresponding Source in the same way through the same place at no further charge. You need not require recipients to copy the Corresponding Source along with the object code. If the place to copy the object code is a network server, the Corresponding Source may be on a different server (operated by you or a third party) that supports equivalent copying facilities, provided you maintain clear directions next to the object code saying where to find the Corresponding Source. Regardless of what server hosts the Corresponding Source, you remain obligated to ensure that it is available for as long as needed to satisfy these requirements.
   5. Convey the object code using peer-to-peer transmission, provided you inform other peers where the object code and Corresponding Source of the work are being offered to the general public at no charge under subsection 6d.

   A separable portion of the object code, whose source code is excluded from the Corresponding Source as a System Library, need not be included in conveying the object code work.

   A “User Product” is either (1) a “consumer product”, which means any tangible personal property which is normally used for personal, family, or household purposes, or (2) anything designed or sold for incorporation into a dwelling. In determining whether a product is a consumer product, doubtful cases shall be resolved in favor of coverage. For a particular product received by a particular user, “normally used” refers to a typical or common use of that class of product, regardless of the status of the particular user or of the way in which the particular user actually uses, or expects or is expected to use, the product. A product is a consumer product regardless of whether the product has substantial commercial, industrial or non-consumer uses, unless such uses represent the only significant mode of use of the product.

   “Installation Information” for a User Product means any methods, procedures, authorization keys, or other information required to install and execute modified versions of a covered work in that User Product from a modified version of its Corresponding Source. The information must suffice to ensure that the continued functioning of the modified object code is in no case prevented or interfered with solely because modification has been made.

   If you convey an object code work under this section in, or with, or specifically for use in, a User Product, and the conveying occurs as part of a transaction in which the right of possession and use of the User Product is transferred to the recipient in perpetuity or for a fixed term (regardless of how the transaction is characterized), the Corresponding Source conveyed under this section must be accompanied by the Installation Information. But this requirement does not apply if neither you nor any third party retains the ability to install modified object code on the User Product (for example, the work has been installed in ROM).

   The requirement to provide Installation Information does not include a requirement to continue to provide support service, warranty, or updates for a work that has been modified or installed by the recipient, or for the User Product in which it has been modified or installed. Access to a network may be denied when the modification itself materially and adversely affects the operation of the network or violates the rules and protocols for communication across the network.

   Corresponding Source conveyed, and Installation Information provided, in accord with this section must be in a format that is publicly documented (and with an implementation available to the public in source code form), and must require no special password or key for unpacking, reading or copying.

8. Additional Terms.

   “Additional permissions” are terms that supplement the terms of this License by making exceptions from one or more of its conditions. Additional permissions that are applicable to the entire Program shall be treated as though they were included in this License, to the extent that they are valid under applicable law. If additional permissions apply only to part of the Program, that part may be used separately under those permissions, but the entire Program remains governed by this License without regard to the additional permissions.

   When you convey a copy of a covered work, you may at your option remove any additional permissions from that copy, or from any part of it. (Additional permissions may be written to require their own removal in certain cases when you modify the work.) You may place additional permissions on material, added by you to a covered work, for which you have or can give appropriate copyright permission.

   Notwithstanding any other provision of this License, for material you add to a covered work, you may (if authorized by the copyright holders of that material) supplement the terms of this License with terms:

   1. Disclaiming warranty or limiting liability differently from the terms of sections 15 and 16 of this License; or
   2. Requiring preservation of specified reasonable legal notices or author attributions in that material or in the Appropriate Legal Notices displayed by works containing it; or
   3. Prohibiting misrepresentation of the origin of that material, or requiring that modified versions of such material be marked in reasonable ways as different from the original version; or
   4. Limiting the use for publicity purposes of names of licensors or authors of the material; or
   5. Declining to grant rights under trademark law for use of some trade names, trademarks, or service marks; or
   6. Requiring indemnification of licensors and authors of that material by anyone who conveys the material (or modified versions of it) with contractual assumptions of liability to the recipient, for any liability that these contractual assumptions directly impose on those licensors and authors.

   All other non-permissive additional terms are considered “further restrictions” within the meaning of section 10. If the Program as you received it, or any part of it, contains a notice stating that it is governed by this License along with a term that is a further restriction, you may remove that term. If a license document contains a further restriction but permits relicensing or conveying under this License, you may add to a covered work material governed by the terms of that license document, provided that the further restriction does not survive such relicensing or conveying.

   If you add terms to a covered work in accord with this section, you must place, in the relevant source files, a statement of the additional terms that apply to those files, or a notice indicating where to find the applicable terms.

   Additional terms, permissive or non-permissive, may be stated in the form of a separately written license, or stated as exceptions; the above requirements apply either way.

9. Termination.

   You may not propagate or modify a covered work except as expressly provided under this License. Any attempt otherwise to propagate or modify it is void, and will automatically terminate your rights under this License (including any patent licenses granted under the third paragraph of section 11).

   However, if you cease all violation of this License, then your license from a particular copyright holder is reinstated (a) provisionally, unless and until the copyright holder explicitly and finally terminates your license, and (b) permanently, if the copyright holder fails to notify you of the violation by some reasonable means prior to 60 days after the cessation.

   Moreover, your license from a particular copyright holder is reinstated permanently if the copyright holder notifies you of the violation by some reasonable means, this is the first time you have received notice of violation of this License (for any work) from that copyright holder, and you cure the violation prior to 30 days after your receipt of the notice.

   Termination of your rights under this section does not terminate the licenses of parties who have received copies or rights from you under this License. If your rights have been terminated and not permanently reinstated, you do not qualify to receive new licenses for the same material under section 10.

10. Acceptance Not Required for Having Copies.

    You are not required to accept this License in order to receive or run a copy of the Program. Ancillary propagation of a covered work occurring solely as a consequence of using peer-to-peer transmission to receive a copy likewise does not require acceptance. However, nothing other than this License grants you permission to propagate or modify any covered work. These actions infringe copyright if you do not accept this License. Therefore, by modifying or propagating a covered work, you indicate your acceptance of this License to do so.

11. Automatic Licensing of Downstream Recipients.

    Each time you convey a covered work, the recipient automatically receives a license from the original licensors, to run, modify and propagate that work, subject to this License. You are not responsible for enforcing compliance by third parties with this License.

    An “entity transaction” is a transaction transferring control of an organization, or substantially all assets of one, or subdividing an organization, or merging organizations. If propagation of a covered work results from an entity transaction, each party to that transaction who receives a copy of the work also receives whatever licenses to the work the party’s predecessor in interest had or could give under the previous paragraph, plus a right to possession of the Corresponding Source of the work from the predecessor in interest, if the predecessor has it or can get it with reasonable efforts.

    You may not impose any further restrictions on the exercise of the rights granted or affirmed under this License. For example, you may not impose a license fee, royalty, or other charge for exercise of rights granted under this License, and you may not initiate litigation (including a cross-claim or counterclaim in a lawsuit) alleging that any patent claim is infringed by making, using, selling, offering for sale, or importing the Program or any portion of it.

12. Patents.

    A “contributor” is a copyright holder who authorizes use under this License of the Program or a work on which the Program is based. The work thus licensed is called the contributor’s “contributor version”.

    A contributor’s “essential patent claims” are all patent claims owned or controlled by the contributor, whether already acquired or hereafter acquired, that would be infringed by some manner, permitted by this License, of making, using, or selling its contributor version, but do not include claims that would be infringed only as a consequence of further modification of the contributor version. For purposes of this definition, “control” includes the right to grant patent sublicenses in a manner consistent with the requirements of this License.

    Each contributor grants you a non-exclusive, worldwide, royalty-free patent license under the contributor’s essential patent claims, to make, use, sell, offer for sale, import and otherwise run, modify and propagate the contents of its contributor version.

    In the following three paragraphs, a “patent license” is any express agreement or commitment, however denominated, not to enforce a patent (such as an express permission to practice a patent or covenant not to sue for patent infringement). To “grant” such a patent license to a party means to make such an agreement or commitment not to enforce a patent against the party.

    If you convey a covered work, knowingly relying on a patent license, and the Corresponding Source of the work is not available for anyone to copy, free of charge and under the terms of this License, through a publicly available network server or other readily accessible means, then you must either (1) cause the Corresponding Source to be so available, or (2) arrange to deprive yourself of the benefit of the patent license for this particular work, or (3) arrange, in a manner consistent with the requirements of this License, to extend the patent license to downstream recipients. “Knowingly relying” means you have actual knowledge that, but for the patent license, your conveying the covered work in a country, or your recipient’s use of the covered work in a country, would infringe one or more identifiable patents in that country that you have reason to believe are valid.

    If, pursuant to or in connection with a single transaction or arrangement, you convey, or propagate by procuring conveyance of, a covered work, and grant a patent license to some of the parties receiving the covered work authorizing them to use, propagate, modify or convey a specific copy of the covered work, then the patent license you grant is automatically extended to all recipients of the covered work and works based on it.

    A patent license is “discriminatory” if it does not include within the scope of its coverage, prohibits the exercise of, or is conditioned on the non-exercise of one or more of the rights that are specifically granted under this License. You may not convey a covered work if you are a party to an arrangement with a third party that is in the business of distributing software, under which you make payment to the third party based on the extent of your activity of conveying the work, and under which the third party grants, to any of the parties who would receive the covered work from you, a discriminatory patent license (a) in connection with copies of the covered work conveyed by you (or copies made from those copies), or (b) primarily for and in connection with specific products or compilations that contain the covered work, unless you entered into that arrangement, or that patent license was granted, prior to 28 March 2007.

    Nothing in this License shall be construed as excluding or limiting any implied license or other defenses to infringement that may otherwise be available to you under applicable patent law.

13. No Surrender of Others’ Freedom.

    If conditions are imposed on you (whether by court order, agreement or otherwise) that contradict the conditions of this License, they do not excuse you from the conditions of this License. If you cannot convey a covered work so as to satisfy simultaneously your obligations under this License and any other pertinent obligations, then as a consequence you may not convey it at all. For example, if you agree to terms that obligate you to collect a royalty for further conveying from those to whom you convey the Program, the only way you could satisfy both those terms and this License would be to refrain entirely from conveying the Program.

14. Use with the GNU Affero General Public License.

    Notwithstanding any other provision of this License, you have permission to link or combine any covered work with a work licensed under version 3 of the GNU Affero General Public License into a single combined work, and to convey the resulting work. The terms of this License will continue to apply to the part which is the covered work, but the special requirements of the GNU Affero General Public License, section 13, concerning interaction through a network will apply to the combination as such.

15. Revised Versions of this License.

    The Free Software Foundation may publish revised and/or new versions of the GNU General Public License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns.

    Each version is given a distinguishing version number. If the Program specifies that a certain numbered version of the GNU General Public License “or any later version” applies to it, you have the option of following the terms and conditions either of that numbered version or of any later version published by the Free Software Foundation. If the Program does not specify a version number of the GNU General Public License, you may choose any version ever published by the Free Software Foundation.

    If the Program specifies that a proxy can decide which future versions of the GNU General Public License can be used, that proxy’s public statement of acceptance of a version permanently authorizes you to choose that version for the Program.

    Later license versions may give you additional or different permissions. However, no additional obligations are imposed on any author or copyright holder as a result of your choosing to follow a later version.

16. Disclaimer of Warranty.

    THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM “AS IS” WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.

17. Limitation of Liability.

    IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

18. Interpretation of Sections 15 and 16.

    If the disclaimer of warranty and limitation of liability provided above cannot be given local legal effect according to their terms, reviewing courts shall apply local law that most closely approximates an absolute waiver of all civil liability in connection with the Program, unless a warranty or assumption of liability accompanies a copy of the Program in return for a fee.

END OF TERMS AND CONDITIONS

How to Apply These Terms to Your New Programs

If you develop a new program, and you want it to be of the greatest possible use to the public, the best way to achieve this is to make it free software which everyone can redistribute and change under these terms.

To do so, attach the following notices to the program. It is safest to attach them to the start of each source file to most effectively state the exclusion of warranty; and each file should have at least the “copyright” line and a pointer to where the full notice is found.

one line to give the program's name and a brief idea of what it does.
Copyright (C) year name of author

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or (at
your option) any later version.

This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see http://www.gnu.org/licenses/.

Also add information on how to contact you by electronic and paper mail.

If the program does terminal interaction, make it output a short notice like this when it starts in an interactive mode:

program Copyright (C) year name of author
This program comes with ABSOLUTELY NO WARRANTY; for details type ‘show w’.
This is free software, and you are welcome to redistribute it
under certain conditions; type ‘show c’ for details.

The hypothetical commands ‘show w’ and ‘show c’ should show the appropriate parts of the General Public License. Of course, your program’s commands might be different; for a GUI interface, you would use an “about box”.

You should also get your employer (if you work as a programmer) or school, if any, to sign a “copyright disclaimer” for the program, if necessary. For more information on this, and how to apply and follow the GNU GPL, see http://www.gnu.org/licenses/.

The GNU General Public License does not permit incorporating your program into proprietary programs. If your program is a subroutine library, you may consider it more useful to permit linking proprietary applications with the library. If this is what you want to do, use the GNU Lesser General Public License instead of this License. But first, please read http://www.gnu.org/philosophy/why-not-lgpl.html.

Index

Footnotes

(1)

Icons are not yet implemented this way in the Braille library, plain texts are displayed instead.

Table of Contents

About This Document

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