1BRLTTY(1)                    BRLTTY User's Manual                    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 table.  Relative paths are anchored
42              at /etc/brltty/Attributes.  The .atb extension is optional.  The
43              built-in default is left_right.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/Contraction.  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:,bluetooth:.
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 bluetooth: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:device.  The serial:
68                     qualifier is optional (for backward compatibility).  If a
69                     relative  path  is given then it's anchored at /dev/ (the
70                     usual location where devices are defined on  a  Unix-like
71                     system).   The  following device specifications all refer
72                     to the primary  serial  device  on  Linux:  serial:ttyS0,
73                     serial:/dev/ttyS0, ttyS0, /dev/ttyS0.
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 interface, e.g. both a
90              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 (commonly used options only),
103              and then exit.
104
105       -i name (--speech-input=)
106              The file system object (FIFO, named  pipe,  named  socket,  etc)
107              which  gives other applications access to brltty's speech driver
108              for text-to-speech conversion.  It's  created  at  start-up  and
109              removed at termination.  Relative paths are anchored at the cur‐
110              rent working directory.  The built-in default is that  the  file
111              system object is not created.
112
113       -k table (--keyboard-table=)
114              The  path to the keyboard table.  Relative paths are anchored at
115              /etc/brltty/Keyboard.  The .ktb extension is optional.
116
117       -l level (--log-level=)
118              The minimum severity level for messages written to the log.  Any
119              of  the  following  numbers, or any abbreviation of their corre‐
120              sponding names, may be specified:
121
122              0   emergency
123
124              1   alert
125
126              2   critical
127
128              3   error
129
130              4   warning
131
132              5   notice
133
134              6   information
135
136              7   debug
137
138       The built-in default is notice.
139
140       -m device (--midi-device=)
141              The device to use for the Musical Instrument Digital  Interface.
142              For  ALSA it's client:port, where each may be either a number or
143              a case-sensitive substring of its name.   For  other  interfaces
144              it's  the full path to an appropriate system device.  The built-
145              in default is:
146
147              Linux/ALSA  the first available MIDI output port
148
149              Linux/OSS   /dev/sequencer
150
151       -n (--no-daemon)
152              Remain in the foreground (useful for debugging).
153
154       -p device (--pcm-device=)
155              The device to use for digital audio.  For ALSA it's  name[:argu‐
156              ment,...].  For other interfaces it's the full path to an appro‐
157              priate system device.  The built-in default is:
158
159              FreeBSD     /dev/dsp
160
161              Linux/ALSA  hw:0,0
162
163              Linux/OSS   /dev/dsp
164
165              NetBSD      /dev/audio
166
167              OpenBSD     /dev/audio
168
169              Qnx         the preferred PCM output device
170
171              Solaris     /dev/audio
172
173       -q (--quiet)
174              Suppress the start-up messages.  This is done  by  reducing  the
175              default  log level (see the -l (--log-level=) option) to warning
176              (information if either -v (--verify) or -V (--version)  is  also
177              specified).
178
179       -r (--release-device)
180              Release  the  device  to  which the braille display is connected
181              when the current screen or window can't be read.
182
183       -s driver,...|auto (--speech-driver=)
184              The driver for the speech  synthesizer  (see  Driver  Specifica‐
185              tion).  The built-in default is auto.
186
187       -t table (--text-table=)
188              The  path  to  the  text  table.  Relative paths are anchored at
189              /etc/brltty/Text.  The .ttb extension is optional.  The built-in
190              default  is  en-nabcc.ttb  (the  North American Braille Computer
191              Code).
192
193       -v (--verify)
194              Print the start-up messages and then exit.  This always includes
195              the  versions  of brltty itself, the server side of its applica‐
196              tion programming interface, and each of the selected braille and
197              speech drivers.  If the -q (--quiet) option isn't also specified
198              then it also includes  the  values  of  the  options  after  all
199              sources  have  been considered.  If more than one braille driver
200              and/or more than one braille  device  has  been  specified  then
201              braille  display  autodetection  is performed.  If more than one
202              speech driver has been specified then speech synthesizer autode‐
203              tection is performed.
204
205       -x driver (--screen-driver=)
206              The  screen  driver.   The  built-in default is operating system
207              appropriate.
208
209       -A name=value,... (--api-parameters=)
210              Parameters for the application programming  interface.   If  the
211              same  parameter  is  specified more than once then the rightmost
212              specification is used.  Parameter names may be abbreviated.
213
214       -B [driver:]name=value,... (--braille-parameters=)
215              Parameters for the braille display driver.  If the same  parame‐
216              ter is specified more than once then the rightmost specification
217              is used.  Parameter names may be abbreviated.   If  a  parameter
218              assignment  is  qualified with a driver identification code then
219              it's only processed if that  braille  display  driver  is  being
220              used.
221
222       -D directory (--drivers-directory=)
223              The  path  to the directory which contains the dynamically load‐
224              able driver objects.  The built-in default is /usr/lib64/brltty.
225
226       -E (--environment-variables)
227              Recognize environment variables.
228
229       -F file (--preferences-file=)
230              The path to the preferences file.  Relative paths  are  anchored
231              at /var/lib/brltty.  The built-in default is brltty.prefs.
232
233       -H (--full-help)
234              Print a command line usage summary (all options), and then exit.
235
236       -I (--install-service)
237              (Windows  only)  Install brltty as the BrlAPI service so that it
238              will be automatically started when the system is booted, and  so
239              that applications can know that a BrlAPI server is running.
240
241       -K arg (--keyboard-properties=)
242              Properties of the keyboard.
243
244       -L file (--log-file=)
245              The  file to which log messages are written.  Relative paths are
246              anchored at the current working directory.  The  default  is  to
247              send log messages to the system log.
248
249       -M csecs (--message-delay=)
250              The  message  hold time in hundredths of a second.  The built-in
251              default is 400 (4 seconds).
252
253       -N (--no-api)
254              Don't start the application programming interface.
255
256       -P file (--pid-file=)
257              The full path to the process identifier file.  If this option is
258              supplied,  brltty  writes  its process identifier (pid) into the
259              specified file at start-up.  The file  is  removed  when  brltty
260              terminates.
261
262       -R (--remove-service)
263              (Windows only) Remove the BrlAPI service so that brltty will not
264              be automatically started when the system is booted, and so  that
265              applications can know that no BrlAPI server is running.
266
267       -S [driver:]name=value,... (--speech-parameters=)
268              Parameters  for  the  speech  synthesizer  driver.   If the same
269              parameter is specified more than once then the rightmost  speci‐
270              fication  is  used.   Parameter  names may be abbreviated.  If a
271              parameter assignment is qualified with a  driver  identification
272              code  then it's only processed if that speech synthesizer driver
273              is being used.
274
275       -T directory (--tables-directory=)
276              The path to the directory which contains the  text,  attributes,
277              contraction,  keyboard,  and input tables.  The built-in default
278              is /etc/brltty.
279
280       -U directory (--updatable-directory=)
281              The path to  a  directory  which  contains  files  that  can  be
282              updated.  The built-in default is /var/lib/brltty.
283
284       -V (--version)
285              Print  the  versions  of  brltty  itself, the server side of its
286              application programming interface, and those drivers which  were
287              configured in at build-time, and then exit.  If the -q (--quiet)
288              option isn't also specified then also print  copyright  informa‐
289              tion.
290
291       -W directory (--writable-directory=)
292              The  path  to a directory which can be written to.  The built-in
293              default is /var/run/brltty.
294
295       -X name=value,... (--screen-parameters=)
296              Parameters for the screen driver.   If  the  same  parameter  is
297              specified  more  than  once  then the rightmost specification is
298              used.  Parameter names may be abbreviated.
299
300       -Y text (--start-message=)
301              The text to be shown when the braille driver starts  and  to  be
302              spoken  when  the speech driver starts.  The built-in default is
303              BRLTTY 6.0.
304
305       -Z text (--stop-message=)
306              The text to be shown when the braille driver stops.  The  built-
307              in default is BRLTTY stopped.
308
309   Environment Variables
310       The  following  environment variables are recognized if the -E (--envi‐
311       ronment-variables) option is specified:
312
313       BRLTTY_API_PARAMETERS=name=value,...
314              Parameters for the application programming interface.   See  the
315              -A (--api-parameters=) option for details.
316
317       BRLTTY_ATTRIBUTES_TABLE=table
318              The  attributes  table.  See the -a (--attributes-table=) option
319              for details.
320
321       BRLTTY_BRAILLE_DEVICE=device,...
322              The device to which the braille display is connected.   See  the
323              -d (--braille-device=) option for details.
324
325       BRLTTY_BRAILLE_DRIVER=driver,...|auto
326              The    driver   for   the   braille   display.    See   the   -b
327              (--braille-driver=) option for details.
328
329       BRLTTY_BRAILLE_PARAMETERS=[driver:]name=value,...
330              Parameters  for  the  braille  display  driver.   See   the   -B
331              (--braille-parameters=) option for details.
332
333       BRLTTY_CONFIGURATION_FILE=file
334              The  configuration  file.   See  the  -f (--configuration-file=)
335              option for details.
336
337       BRLTTY_CONTRACTION_TABLE=table
338              The contraction table.  See the -c (--contraction-table=) option
339              for details.
340
341       BRLTTY_MIDI_DEVICE=device
342              The  device to use for the Musical Instrument Digital Interface.
343              See the -m (--midi-device=) option for details.
344
345       BRLTTY_PCM_DEVICE=device
346              The device to use for digital audio.  See the -p (--pcm-device=)
347              option for details.
348
349       BRLTTY_PREFERENCES_FILE=file
350              The  preferences  file.  See the -F (--preferences-file=) option
351              for details.
352
353       BRLTTY_RELEASE_DEVICE=on|off
354              Release the device to which the  braille  display  is  connected
355              when  the  current  screen  or window can't be read.  See the -r
356              (--release-device) option for details.
357
358       BRLTTY_SCREEN_DRIVER=driver
359              The screen driver.  See the  -x  (--screen-driver=)  option  for
360              details.
361
362       BRLTTY_SCREEN_PARAMETERS=name=value,...
363              Parameters  for the screen driver.  See the -X (--screen-parame‐
364              ters=) option for details.
365
366       BRLTTY_SPEECH_DRIVER=driver,...|auto
367              The  driver  for   the   speech   synthesizer.    See   the   -s
368              (--speech-driver=) option for details.
369
370       BRLTTY_SPEECH_INPUT=name
371              The  file system object which gives other applications access to
372              brltty's speech driver for text-to-speech conversion.   See  the
373              -i (--speech-input=) option for details.
374
375       BRLTTY_SPEECH_PARAMETERS=[driver:]name=value,...
376              Parameters  for  the  speech  synthesizer  driver.   See  the -S
377              (--speech-parameters=) option for details.
378
379       BRLTTY_TEXT_TABLE=table
380              The text table.  See the -t (--text-table=) option for details.
381
382   The Configuration File
383       Blank lines are ignored.  If the character # occurs on  any  line  then
384       all  characters  from  it to the end of that line are treated as a com‐
385       ment.
386
387       The following configuration directives are supported:
388
389       api-parameters name=value,...
390              Parameters for the application programming interface.   See  the
391              -A (--api-parameters=) option for details.
392
393       attributes-table table
394              The  attributes  table.  See the -a (--attributes-table=) option
395              for details.
396
397       braille-device device,...
398              The device to which the braille display is connected.   See  the
399              -d (--braille-device=) option for details.
400
401       braille-driver driver,...|auto
402              The    driver   for   the   braille   display.    See   the   -b
403              (--braille-driver=) option for details.
404
405       braille-parameters [driver:]name=value,...
406              Parameters  for  the  braille  display  driver.   See   the   -B
407              (--braille-parameters=) option for details.
408
409       contraction-table table
410              The contraction table.  See the -c (--contraction-table=) option
411              for details.
412
413       midi-device device
414              The device to use for the Musical Instrument Digital  Interface.
415              See the -m (--midi-device=) option for details.
416
417       pcm-device device
418              The device to use for digital audio.  See the -p (--pcm-device=)
419              option for details.
420
421       preferences-file file
422              The preferences file.  See the -F  (--preferences-file=)  option
423              for details.
424
425       release-device on|off
426              Release  the  device  to  which the braille display is connected
427              when the current screen or window can't be  read.   See  the  -r
428              (--release-device) option for details.
429
430       screen-driver driver
431              The  screen  driver.   See  the -x (--screen-driver=) option for
432              details.
433
434       screen-parameters name=value,...
435              Parameters for the screen driver.  See the -X  (--screen-parame‐
436              ters=) option for details.
437
438       speech-driver driver,...|auto
439              The   driver   for   the   speech   synthesizer.    See  the  -s
440              (--speech-driver=) option for details.
441
442       speech-input 0me
443              The file system object which gives other applications access  to
444              brltty's  speech  driver for text-to-speech conversion.  See the
445              -i (--speech-input=) option for details.
446
447       speech-parameters [driver:]name=value,...
448              Parameters for  the  speech  synthesizer  driver.   See  the  -S
449              (--speech-parameters=) option for details.
450
451       text-table table
452              The text table.  See the -t (--text-table=) option for details.
453
454   Driver Specification
455       A  braille  display  or speech synthesizer driver must be specified via
456       its identification code:
457
458              al  Alva
459
460              an  Android
461
462              at  Albatross
463
464              ba  BrlAPI
465
466              bc  BrailComm
467
468              bd  Braudi
469
470              bg  B2G
471
472              bl  BrailleLite
473
474              bm  Baum
475
476              bn  BrailleNote
477
478              cb  CombiBraille
479
480              ec  EcoBraille
481
482              en  eSpeak-NG
483
484              es  eSpeak
485
486              eu  EuroBraille
487
488              fl  FestivalLite
489
490              fs  FreedomScientific
491
492              fv  Festival
493
494              gs  GenericSay
495
496              hd  Hedo
497
498              hm  HIMS
499
500              ht  HandyTech
501
502              hw  HumanWare
503
504              ir  Iris
505
506              ic  Inceptor
507
508              lb  Libbraille
509
510              lt  LogText
511
512              mb  MultiBraille
513
514              md  MDV
515
516              mm  BrailleMemo
517
518              mn  MiniBraille
519
520              mp  Mikropuhe
521
522              mt  Metec
523
524              no  no driver
525
526              np  NinePoint
527
528              pg  Pegasus
529
530              pm  Papenmeier
531
532              sd  SpeechDispatcher
533
534              sk  Seika
535
536              sw  Swift
537
538              th  Theta
539
540              tn  TechniBraille Systems Inc.
541
542              ts  Telesensory Systems Inc.
543
544              tt  TTY
545
546              vd  VideoBraille
547
548              vo  Voyager, Part232 (serial adapter), BraillePen/EasyLink
549
550              vr  Virtual
551
552              vs  VisioBraille
553
554              vv  ViaVoice
555
556              xs  ExternalSpeech
557
558              xw  XWindow
559
560              A comma-delimited list of drivers may be specified.  If this  is
561              done then autodetection is performed using each listed driver in
562              sequence.  You may need to experiment in order to determine  the
563              most  reliable  order  since some drivers autodetect better than
564              others.
565
566              If the single word auto is specified then autodetection is  per‐
567              formed  using  only those drivers which are known to be reliable
568              for this purpose.
569

SEE ALSO

571       For   full   documentation,   see   brltty's    on-line    manual    at
572       [http://brltty.app/documentation.html].
573
574
575
576brltty 6.0                        2019-02-22                         BRLTTY(1)
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