1BRLTTY(1)                     The BRLTTY Project                     BRLTTY(1)
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NAME

6       brltty - refreshable braille display driver for Linux/Unix
7

SYNOPSIS

9       brltty [option ...]
10

DESCRIPTION

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

OPTIONS

19       Options  can  be  passed  to  brltty in a number of ways.  From most to
20       least influential, these are:
21
22       1.  Command Line Options
23
24       2.  Boot Parameters
25
26       3.  Environment Variables (if the -E  (--environment-variables)  option
27           is in effect)
28
29       4.  The Configuration File
30
31       5.  Built-in Defaults
32
33   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
38       The following options are supported:
39
40       -a table (--attributes-table=)
41              The  path  to  the attributes translation table.  Relative paths
42              are anchored at /etc/brltty/.  The .atb extension  is  optional.
43              The built-in default is attributes.atb.
44
45       -b driver,...|auto (--braille-driver=)
46              The  driver  for the braille display (see Driver Specification).
47              The built-in default is auto.
48
49       -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
53       -d device,... (--braille-device=)
54              The  device  to  which  the  braille  display is connected.  The
55              built-in default is usb:.
56
57              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
62              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
67              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
75              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
86              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
92       -e (--standard-error)
93              Write logs to standard error rather than to the system log (use‐
94              ful for debugging).
95
96       -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
101       -h (--help)
102              Print a command line usage summary and then exit.
103
104       -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
109              0   emergency
110
111              1   alert
112
113              2   critical
114
115              3   error
116
117              4   warning
118
119              5   notice
120
121              6   information
122
123              7   debug
124
125       The built-in default is notice.
126
127       -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
134              Linux/ALSA  the first available MIDI output port
135
136              Linux/OSS   /dev/sequencer
137
138       -n (--no-daemon)
139              Remain in the foreground (useful for debugging).
140
141       -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
146              FreeBSD     /dev/dsp
147
148              Linux/ALSA  hw:0,0
149
150              Linux/OSS   /dev/dsp
151
152              NetBSD      /dev/audio
153
154              OpenBSD     /dev/audio
155
156              Qnx         the preferred PCM output device
157
158              Solaris     /dev/audio
159
160       -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
166       -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
170       -s driver,...|auto (--speech-driver=)
171              The  driver  for  the  speech synthesizer (see Driver Specifica‐
172              tion).  The built-in default is auto.
173
174       -t table (--text-table=)
175              The path to the text  translation  table.   Relative  paths  are
176              anchored  at /etc/brltty/.  The .ttb extension is optional.  The
177              built-in default is nabcc.ttb (the North American  Braille  Com‐
178              puter Code).
179
180       -v (--verify)
181              Print the start-up messages and then exit.  This always includes
182              the versions of brltty itself, the server side of  its  applica‐
183              tion programming interface, and each of the selected braille and
184              speech drivers.  If the -q (--quiet) option isn't also specified
185              then  it  also  includes  the  values  of  the options after all
186              sources have been considered.  If more than one  braille  driver
187              and/or  more  than  one  braille  device has been specified then
188              braille display autodetection is performed.  If  more  than  one
189              speech driver has been specified then speech synthesizer autode‐
190              tection is performed.
191
192       -x driver (--screen-driver=)
193              The screen driver.  The built-in  default  is  operating  system
194              appropriate.
195
196       -A name=value,... (--api-parameters=)
197              Parameters  for  the  application programming interface.  If the
198              same parameter is specified more than once  then  the  rightmost
199              specification is used.  Parameter names may be abbreviated.
200
201       -B [driver:]name=value,... (--braille-parameters=)
202              Parameters  for the braille display driver.  If the same parame‐
203              ter is specified more than once then the rightmost specification
204              is  used.   Parameter  names may be abbreviated.  If a parameter
205              assignment is qualified with a driver identification  code  then
206              it's  only  processed  if  that  braille display driver is being
207              used.
208
209       -E (--environment-variables)
210              Recognize environment variables.
211
212       -F fifo (--speech-fifo=)
213              The FIFO which  gives  other  applications  access  to  brltty's
214              speech driver.  It's created at start-up and removed at termina‐
215              tion.  Relative paths are anchored at /etc/brltty/.  The  built-
216              in default is that no FIFO is created.
217
218       -I (--install-service)
219              (Windows  only)  Install brltty as the BrlAPI service so that it
220              will be automatically started when the system is booted  and  so
221              that applications can know that a BrlAPI server is running.
222
223       -M csecs (--message-delay=)
224              The  message  hold time in hundredths of a second.  The built-in
225              default is 400 (4 seconds).
226
227       -N (--no-api)
228              Don't start the application programming interface.
229
230       -P file (--pid-file=)
231              The full path to the process identifier file.  If this option is
232              supplied,  brltty  writes  its process identifier (pid) into the
233              specified file at start-up.  The file  is  removed  when  brltty
234              terminates.
235
236       -R (--remove-service)
237              (Windows only) Remove the BrlAPI service so that brltty will not
238              be automatically started when the system is booted and  so  that
239              applications can know that no BrlAPI server is running.
240
241       -S [driver:]name=value,... (--speech-parameters=)
242              Parameters  for  the  speech  synthesizer  driver.   If the same
243              parameter is specified more than once then the rightmost  speci‐
244              fication  is  used.   Parameter  names may be abbreviated.  If a
245              parameter assignment is qualified with a  driver  identification
246              code  then it's only processed if that speech synthesizer driver
247              is being used.
248
249       -U csecs (--update-interval=)
250              The braille window update interval in hundredths  of  a  second.
251              The built-in default is 4 (25 times per second).
252
253       -V (--version)
254              Print  the  versions  of  brltty  itself, the server side of its
255              application programming interface, and those drivers which  were
256              configured in at build-time, and then exit.  If the -q (--quiet)
257              option isn't also specified then also print  copyright  informa‐
258              tion.
259
260       -X name=value,... (--screen-parameters=)
261              Parameters  for  the  screen  driver.   If the same parameter is
262              specified more than once then  the  rightmost  specification  is
263              used.  Parameter names may be abbreviated.
264
265   Environment Variables
266       The  following  environment variables are recognized if the -E (--envi‐
267       ronment-variables) option is specified:
268
269       BRLTTY_API_PARAMETERS=name=value,...
270              Parameters for the application programming interface.   See  the
271              -A (--api-parameters=) option for details.
272
273       BRLTTY_ATTRIBUTES_TABLE=table
274              The  attributes translation table.  See the -a (--attributes-ta‐
275              ble=) option for details.
276
277       BRLTTY_BRAILLE_DEVICE=device,...
278              The device to which the braille display is connected.   See  the
279              -d (--braille-device=) option for details.
280
281       BRLTTY_BRAILLE_DRIVER=driver,...|auto
282              The  driver  for  the  braille  display.  See the -b (--braille-
283              driver=) option for details.
284
285       BRLTTY_BRAILLE_PARAMETERS=[driver:]name=value,...
286              Parameters  for  the  braille  display  driver.   See   the   -B
287              (--braille-parameters=) option for details.
288
289       BRLTTY_CONFIGURATION_FILE=file
290              The  configuration  file.   See  the  -f (--configuration-file=)
291              option for details.
292
293       BRLTTY_CONTRACTION_TABLE=table
294              The contraction table.  See the -c (--contraction-table=) option
295              for details.
296
297       BRLTTY_MIDI_DEVICE=device
298              The  device to use for the Musical Instrument Digital Interface.
299              See the -m (--midi-device=) option for details.
300
301       BRLTTY_PCM_DEVICE=device
302              The device to use for digital audio.  See the -p (--pcm-device=)
303              option for details.
304
305       BRLTTY_RELEASE_DEVICE=on|off
306              Release  the  device  to  which the braille display is connected
307              when the current screen or window can't be  read.   See  the  -r
308              (--release-device) option for details.
309
310       BRLTTY_SCREEN_DRIVER=driver
311              The  screen  driver.   See  the -x (--screen-driver=) option for
312              details.
313
314       BRLTTY_SCREEN_PARAMETERS=name=value,...
315              Parameters for the screen driver.  See the -X  (--screen-parame‐
316              ters=) option for details.
317
318       BRLTTY_SPEECH_DRIVER=driver,...|auto
319              The  driver  for  the speech synthesizer.  See the -s (--speech-
320              driver=) option for details.
321
322       BRLTTY_SPEECH_FIFO=fifo
323              The FIFO which  gives  other  applications  access  to  brltty's
324              speech driver.  See the -F (--speech-fifo=) option for details.
325
326       BRLTTY_SPEECH_PARAMETERS=[driver:]name=value,...
327              Parameters  for  the  speech  synthesizer  driver.   See  the -S
328              (--speech-parameters=) option for details.
329
330       BRLTTY_TEXT_TABLE=table
331              The text translation table.  See the -t  (--text-table=)  option
332              for details.
333
334   The Configuration File
335       Blank  lines  are  ignored.  If the character # occurs on any line then
336       all characters from it to the end of that line are treated  as  a  com‐
337       ment.
338
339       The following configuration directives are supported:
340
341       api-parameters name=value,...
342              Parameters  for  the application programming interface.  See the
343              -A (--api-parameters=) option for details.
344
345       attributes-table table
346              The attributes translation table.  See the -a  (--attributes-ta‐
347              ble=) option for details.
348
349       braille-device device,...
350              The  device  to which the braille display is connected.  See the
351              -d (--braille-device=) option for details.
352
353       braille-driver driver,...|auto
354              The driver for the braille  display.   See  the  -b  (--braille-
355              driver=) option for details.
356
357       braille-parameters [driver:]name=value,...
358              Parameters   for   the  braille  display  driver.   See  the  -B
359              (--braille-parameters=) option for details.
360
361       contraction-table table
362              The contraction table.  See the -c (--contraction-table=) option
363              for details.
364
365       midi-device device
366              The  device to use for the Musical Instrument Digital Interface.
367              See the -m (--midi-device=) option for details.
368
369       pcm-device device
370              The device to use for digital audio.  See the -p (--pcm-device=)
371              option for details.
372
373       release-device on|off
374              Release  the  device  to  which the braille display is connected
375              when the current screen or window can't be  read.   See  the  -r
376              (--release-device) option for details.
377
378       screen-driver driver
379              The  screen  driver.   See  the -x (--screen-driver=) option for
380              details.
381
382       screen-parameters name=value,...
383              Parameters for the screen driver.  See the -X  (--screen-parame‐
384              ters=) option for details.
385
386       speech-driver driver,...|auto
387              The  driver  for  the speech synthesizer.  See the -s (--speech-
388              driver=) option for details.
389
390       speech-fifo fifo
391              The FIFO which  gives  other  applications  access  to  brltty's
392              speech driver.  See the -F (--speech-fifo=) option for details.
393
394       speech-parameters [driver:]name=value,...
395              Parameters  for  the  speech  synthesizer  driver.   See  the -S
396              (--speech-parameters=) option for details.
397
398       text-table table
399              The text translation table.  See the -t  (--text-table=)  option
400              for details.
401
402   Driver Specification
403       A  braille  display  or speech synthesizer driver must be specified via
404       its identification code:
405
406              al  Alva
407
408              at  Albatross
409
410              ba  BrlAPI
411
412              bd  Braudi
413
414              bl  BrailleLite
415
416              bm  Baum
417
418              bn  BrailleNote
419
420              cb  CombiBraille
421
422              ec  EcoBraille
423
424              es  eSpeak
425
426              eu  EuroBraille
427
428              fl  FestivalLite
429
430              fs  FreedomScientific
431
432              fv  Festival
433
434              gs  GenericSay
435
436              hm  HIMS
437
438              ht  HandyTech
439
440              il  IrisLinux
441
442              lb  Libbraille
443
444              lt  LogText
445
446              mb  MultiBraille
447
448              md  MDV
449
450              mn  MiniBraille
451
452              mp  Mikropuhe
453
454              mt  Metec
455
456              no  no driver
457
458              pg  Pegasus
459
460              pm  Papenmeier
461
462              sd  SpeechDispatcher
463
464              sk  Seika
465
466              sw  Swift
467
468              th  Theta
469
470              tn  TechniBraille Systems Inc.
471
472              ts  Telesensory Systems Inc.
473
474              tt  TTY
475
476              vd  VideoBraille
477
478              vo  Voyager
479
480              vr  Virtual
481
482              vs  VisioBraille
483
484              vv  ViaVoice
485
486              xs  ExternalSpeech
487
488              xw  XWindow
489
490              A comma-delimited list of drivers may be specified.  If this  is
491              done then autodetection is performed using each listed driver in
492              sequence.  You may need to experiment in order to determine  the
493              most  reliable  order  since some drivers autodetect better than
494              others.
495
496              If the single word auto is specified then autodetection is  per‐
497              formed  using  only those drivers which are known to be reliable
498              for this purpose.
499

SEE ALSO

501       For   full   documentation,   see   brltty's    on-line    manual    at
502       [http://mielke.cc/brltty/doc/Manual-HTML/Manual.html].
503
504
505
506brltty 4.2                         May 2010                          BRLTTY(1)
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