1BRLTTY(1) The BRLTTY Project BRLTTY(1)
2
6 brltty - refreshable braille display driver for Linux/Unix
7
9 brltty [option ...]
10
12 brltty is a background process (daemon) which provides access to the
13 console screen (when in text mode) for a blind person using a refresh‐
14 able braille display. It drives the braille display, and provides com‐
15 plete screen review functionality. Some speech capability has also
16 been incorporated.
17
19 Options can be passed to brltty in a number of ways. From most to
20 least influential, these are:
21 1. Command Line Options
23 2. Boot Parameters
25 3. Environment Variables (if the -E (--environment-variables) option
27 is in effect)
28 4. The Configuration File
30 5. Built-in Defaults
32 Command Line Options
34 The options are processed sequentially from left to right. If an
35 option is specified more than once, or in case of a conflict, the
36 rightmost specification takes precedence.
37 The following options are supported:
39 -a table (--attributes-table=)
41 The path to the attributes translation table. Relative paths
42 are anchored at /etc/brltty/. The .tbl extension is optional.
43 The built-in default is attributes.tbl.
44 -b driver,...|auto (--braille-driver=)
46 The driver for the braille display (see Driver Specification).
47 The built-in default is auto.
48 -c table (--contraction-table=)
50 The path to the contraction table. Relative paths are anchored
51 at /etc/brltty/. The .ctb extension is optional.
52 -d device,... (--braille-device=)
54 The device to which the braille display is connected. The
55 built-in default is usb:.
56 The general form of a braille device specification is quali‐
58 fier:data. For backward compatibility with earlier releases, if
59 the qualifier is omitted then serial: is assumed. The following
60 device types are supported:
61 Bluetooth
63 For a bluetooth device, specify bluez:address. The
64 address must be six two-digit hexadecimal numbers sepa‐
65 rated by colons, e.g. 01:23:45:67:89:AB.
66 Serial For a serial device, specify serial:/path/to/device. The
68 serial: qualifier is optional (for backward compatibil‐
69 ity). If a relative path is given then it's anchored at
70 /dev/ (the usual location where devices are defined on a
71 Unix-like system). The following device specifications
72 all refer to the primary serial device: serial:/dev/,
73 serial:, /dev/, .
74 USB For a USB device, specify usb:. brltty will search for
76 the first USB device which matches the braille display
77 driver being used. If this is inadequate, e.g. if you
78 have more than one USB braille display which requires the
79 same driver, then you can refine the device specification
80 by appending the serial number of the display to it, e.g.
81 usb:12345. N.B.: The "identification by serial number"
82 feature doesn't work for some models because some manu‐
83 facturers either don't set the USB serial number descrip‐
84 tor at all or do set it but not to a unique value.
85 A comma-delimited list of braille devices may be specified. If
87 this is done then autodetection is performed on each listed
88 device in sequence. This feature is particularly useful if you
89 have a braille display with more than one interrface, e.g. both
90 a serial and a USB port.
91 -e (--standard-error)
93 Write logs to standard error rather than to the system log (use‐
94 ful for debugging).
95 -f file (--configuration-file=)
97 The path to the configuration file. Relative paths are anchored
98 at the current working directory. The built-in default is
99 /etc/brltty.conf.
100 -h (--help)
102 Print a command line usage summary and then exit.
103 -l level (--log-level=)
105 The minimum severity level for messages written to the log. Any
106 of the following numbers, or any abbreviation of their corre‐
107 sponding names, may be specified:
108 0 emergency
110 1 alert
112 2 critical
114 3 error
116 4 warning
118 5 notice
120 6 information
122 7 debug
124 The built-in default is notice.
126 -m device (--midi-device=)
128 The device to use for the Musical Instrument Digital Interface.
129 For ALSA it's client:port, where each may be either a number or
130 a case-sensitive substring of its name. For other interfaces
131 it's the full path to an appropriate system device. The built-
132 in default is:
133 Linux/ALSA the first available MIDI output port
135 Linux/OSS /dev/sequencer
137 -n (--no-daemon)
139 Remain in the foreground (useful for debugging).
140 -p device (--pcm-device=)
142 The device to use for digital audio. For ALSA it's name[:argu‐
143 ment,...]. For other interfaces it's the full path to an appro‐
144 priate system device. The built-in default is:
145 FreeBSD /dev/dsp
147 Linux/ALSA hw:0,0
149 Linux/OSS /dev/dsp
151 NetBSD /dev/audio
153 OpenBSD /dev/audio
155 Qnx the preferred PCM output device
157 Solaris /dev/audio
159 -q (--quiet)
161 Suppress the start-up messages. This is done by reducing the
162 default log level (see the -l (--log-level=) option) to warning
163 (information if either -v (--verify) or -V (--version) is also
164 specified).
165 -r (--release-device)
167 Release the device to which the braille display is connected
168 when the current screen or window can't be read.
169 -s driver,...|auto (--speech-driver=)
171 The driver for the speech synthesizer (see Driver Specifica‐
172 tion). The built-in default is auto.
173 -t table (--text-table=)
175 The path to the text translation table. Relative paths are
176 anchored at /etc/brltty/. The .tbl extension is optional. For
177 a simple file name, the text. prefix is optional. The built-in
178 default is text.nabcc.tbl (the North American Braille Computer
179 Code).
180 -v (--verify)
182 Print the start-up messages and then exit. This always includes
183 the versions of brltty itself, the server side of its applica‐
184 tion programming interface, and each of the selected braille and
185 speech drivers. If the -q (--quiet) option isn't also specified
186 then it also includes the values of the options after all
187 sources have been considered. If more than one braille driver
188 and/or more than one braille device has been specified then
189 braille display autodetection is performed. If more than one
190 speech driver has been specified then speech synthesizer autode‐
191 tection is performed.
192 -x driver (--screen-driver=)
194 The screen driver. The built-in default is operating system
195 appropriate.
196 -A name=value,... (--api-parameters=)
198 Parameters for the application programming interface. If the
199 same parameter is specified more than once then the rightmost
200 specification is used. Parameter names may be abbreviated.
201 -B [driver:]name=value,... (--braille-parameters=)
203 Parameters for the braille display driver. If the same parame‐
204 ter is specified more than once then the rightmost specification
205 is used. Parameter names may be abbreviated. If a parameter
206 assignment is qualified with a driver identification code then
207 it's only processed if that braille display driver is being
208 used.
209 -E (--environment-variables)
211 Recognize environment variables.
212 -F fifo (--speech-fifo=)
214 The FIFO which gives other applications access to brltty's
215 speech driver. It's created at start-up and removed at termina‐
216 tion. Relative paths are anchored at /etc/brltty/. The built-
217 in default is that no FIFO is created.
218 -M csecs (--message-delay=)
220 The message hold time in hundredths of a second. The built-in
221 default is 400 (4 seconds).
222 -N (--no-api)
224 Don't start the application programming interface.
225 -P file (--pid-file=)
227 The full path to the process identifier file. If this option is
228 supplied, brltty writes its process identifier (pid) into the
229 specified file at start-up. The file is removed when brltty
230 terminates.
231 -S [driver:]name=value,... (--speech-parameters=)
233 Parameters for the speech synthesizer driver. If the same
234 parameter is specified more than once then the rightmost speci‐
235 fication is used. Parameter names may be abbreviated. If a
236 parameter assignment is qualified with a driver identification
237 code then it's only processed if that speech synthesizer driver
238 is being used.
239 -U csecs (--update-interval=)
241 The braille window update interval in hundredths of a second.
242 The built-in default is 4 (25 times per second).
243 -V (--version)
245 Print the versions of brltty itself, the server side of its
246 application programming interface, and those drivers which were
247 configured in at build-time, and then exit. If the -q (--quiet)
248 option isn't also specified then also print copyright informa‐
249 tion.
250 -X name=value,... (--screen-parameters=)
252 Parameters for the screen driver. If the same parameter is
253 specified more than once then the rightmost specification is
254 used. Parameter names may be abbreviated.
255 Environment Variables
257 The following environment variables are recognized if the -E (--envi‐
258 ronment-variables) option is specified:
259 BRLTTY_API_PARAMETERS=name=value,...
261 Parameters for the application programming interface. See the
262 -A (--api-parameters=) option for details.
263 BRLTTY_ATTRIBUTES_TABLE=table
265 The attributes translation table. See the -a (--attributes-ta‐
266 ble=) option for details.
267 BRLTTY_BRAILLE_DEVICE=device,...
269 The device to which the braille display is connected. See the
270 -d (--braille-device=) option for details.
271 BRLTTY_BRAILLE_DRIVER=driver,...|auto
273 The driver for the braille display. See the -b (--braille-
274 driver=) option for details.
275 BRLTTY_BRAILLE_PARAMETERS=[driver:]name=value,...
277 Parameters for the braille display driver. See the -B
278 (--braille-parameters=) option for details.
279 BRLTTY_CONFIGURATION_FILE=file
281 The configuration file. See the -f (--configuration-file=)
282 option for details.
283 BRLTTY_CONTRACTION_TABLE=table
285 The contraction table. See the -c (--contraction-table=) option
286 for details.
287 BRLTTY_MIDI_DEVICE=device
289 The device to use for the Musical Instrument Digital Interface.
290 See the -m (--midi-device=) option for details.
291 BRLTTY_PCM_DEVICE=device
293 The device to use for digital audio. See the -p (--pcm-device=)
294 option for details.
295 BRLTTY_RELEASE_DEVICE=on|off
297 Release the device to which the braille display is connected
298 when the current screen or window can't be read. See the -r
299 (--release-device) option for details.
300 BRLTTY_SCREEN_DRIVER=driver
302 The screen driver. See the -x (--screen-driver=) option for
303 details.
304 BRLTTY_SCREEN_PARAMETERS=name=value,...
306 Parameters for the screen driver. See the -X (--screen-parame‐
307 ters=) option for details.
308 BRLTTY_SPEECH_DRIVER=driver,...|auto
310 The driver for the speech synthesizer. See the -s (--speech-
311 driver=) option for details.
312 BRLTTY_SPEECH_FIFO=fifo
314 The FIFO which gives other applications access to brltty's
315 speech driver. See the -F (--speech-fifo=) option for details.
316 BRLTTY_SPEECH_PARAMETERS=[driver:]name=value,...
318 Parameters for the speech synthesizer driver. See the -S
319 (--speech-parameters=) option for details.
320 BRLTTY_TEXT_TABLE=table
322 The text translation table. See the -t (--text-table=) option
323 for details.
324 The Configuration File
326 Blank lines are ignored. If the character # occurs on any line then
327 all characters from it to the end of that line are treated as a com‐
328 ment.
329 The following configuration directives are supported:
331 api-parameters name=value,...
333 Parameters for the application programming interface. See the
334 -A (--api-parameters=) option for details.
335 attributes-table table
337 The attributes translation table. See the -a (--attributes-ta‐
338 ble=) option for details.
339 braille-device device,...
341 The device to which the braille display is connected. See the
342 -d (--braille-device=) option for details.
343 braille-driver driver,...|auto
345 The driver for the braille display. See the -b (--braille-
346 driver=) option for details.
347 braille-parameters [driver:]name=value,...
349 Parameters for the braille display driver. See the -B
350 (--braille-parameters=) option for details.
351 contraction-table table
353 The contraction table. See the -c (--contraction-table=) option
354 for details.
355 midi-device device
357 The device to use for the Musical Instrument Digital Interface.
358 See the -m (--midi-device=) option for details.
359 pcm-device device
361 The device to use for digital audio. See the -p (--pcm-device=)
362 option for details.
363 release-device on|off
365 Release the device to which the braille display is connected
366 when the current screen or window can't be read. See the -r
367 (--release-device) option for details.
368 screen-driver driver
370 The screen driver. See the -x (--screen-driver=) option for
371 details.
372 screen-parameters name=value,...
374 Parameters for the screen driver. See the -X (--screen-parame‐
375 ters=) option for details.
376 speech-driver driver,...|auto
378 The driver for the speech synthesizer. See the -s (--speech-
379 driver=) option for details.
380 speech-fifo fifo
382 The FIFO which gives other applications access to brltty's
383 speech driver. See the -F (--speech-fifo=) option for details.
384 speech-parameters [driver:]name=value,...
386 Parameters for the speech synthesizer driver. See the -S
387 (--speech-parameters=) option for details.
388 text-table table
390 The text translation table. See the -t (--text-table=) option
391 for details.
392 Driver Specification
394 A braille display or speech synthesizer driver must be specified via
395 its identification code:
396 al Alva
398 at Albatross
400 ba BrlAPI
402 bd Braudi
404 bl BrailleLite
406 bm Baum
408 bn BrailleNote
410 cb CombiBraille
412 ec EcoBraille
414 es ExternalSpeech
416 eu EuroBraille
418 fl FestivalLite
420 fs FreedomScientific
422 fv Festival
424 gs GenericSay
426 ht HandyTech
428 il IrisLinux
430 lb Libbraille
432 lt LogText
434 mb MultiBraille
436 md MDV
438 mn MiniBraille
440 mp Mikropuhe
442 no no driver
444 pm Papenmeier
446 sd SpeechDispatcher
448 sw Swift
450 th Theta
452 tn TechniBraille Systems Inc.
454 ts Telesensory Systems Inc.
456 tt TTY
458 vd VideoBraille
460 vo Voyager
462 vr Virtual
464 vs VisioBraille
466 vv ViaVoice
468 xw XWindow
470 A comma-delimited list of drivers may be specified. If this is
472 done then autodetection is performed using each listed driver in
473 sequence. You may need to experiment in order to determine the
474 most reliable order since some drivers autodetect better than
475 others.
476 If the single word auto is specified then autodetection is per‐
478 formed using only those drivers which are known to be reliable
479 for this purpose.
480
482 For full documentation, see brltty's on-line manual at
483 [http://mielke.cc/brltty/doc/Manual-HTML/Manual.html].
484brltty 3.8 June 2007 BRLTTY(1)