Provided by: brltty_5.6-5ubuntu1_amd64 bug

NAME

       brltty - refreshable braille display driver for Linux/Unix

SYNOPSIS

       brltty [option ...]

DESCRIPTION

       brltty  is a background process (daemon) which provides access to the console screen (when
       in text mode) for a blind person using a  refreshable  braille  display.   It  drives  the
       braille   display,  and  provides  complete  screen  review  functionality.   Some  speech
       capability has also been incorporated.

OPTIONS

       Options can be passed to brltty in a number of ways.   From  most  to  least  influential,
       these are:

       1.  Command Line Options

       2.  Boot Parameters

       3.  Environment Variables (if the -E (--environment-variables) option is in effect)

       4.  The Configuration File

       5.  Built-in Defaults

   Command Line Options
       The options are processed sequentially from left to right.  If an option is specified more
       than once, or in case of a conflict, the rightmost specification takes precedence.

       The following options are supported:

       -a table (--attributes-table=)
              The  path  to   the   attributes   table.    Relative   paths   are   anchored   at
              /etc/brltty/Attributes.   The  .atb extension is optional.  The built-in default is
              left_right.atb.

       -b driver,...|auto (--braille-driver=)
              The driver for the  braille  display  (see  Driver  Specification).   The  built-in
              default is auto.

       -c table (--contraction-table=)
              The   path   to   the   contraction   table.    Relative   paths  are  anchored  at
              /etc/brltty/Contraction.  The .ctb extension is optional.

       -d device,... (--braille-device=)
              The device to which the braille display is  connected.   The  built-in  default  is
              usb:,bluetooth:.

              The general form of a braille device specification is qualifier:data.  For backward
              compatibility with earlier releases, if the qualifier is omitted  then  serial:  is
              assumed.  The following device types are supported:

              Bluetooth
                     For  a bluetooth device, specify bluetooth:address.  The address must be six
                     two-digit hexadecimal numbers separated by colons, e.g.  01:23:45:67:89:AB.

              Serial For a serial  device,  specify  serial:device.   The  serial:  qualifier  is
                     optional  (for  backward  compatibility).   If a relative path is given then
                     it's anchored at /dev/ (the usual location where devices are  defined  on  a
                     Unix-like  system).   The  following  device specifications all refer to the
                     primary serial device  on  Linux:  serial:ttyS0,  serial:/dev/ttyS0,  ttyS0,
                     /dev/ttyS0.

              USB    For a USB device, specify usb:.  brltty will search for the first USB device
                     which matches the braille display driver being used.  If this is inadequate,
                     e.g.  if  you have more than one USB braille display which requires the same
                     driver, then you can refine the device specification by appending the serial
                     number  of the display to it, e.g.  usb:12345.  N.B.: The "identification by
                     serial  number"  feature  doesn't  work  for  some   models   because   some
                     manufacturers either don't set the USB serial number descriptor at all or do
                     set it but not to a unique value.

              A comma-delimited list of braille devices may be specified.  If this is  done  then
              autodetection  is  performed  on  each  listed device in sequence.  This feature is
              particularly useful if you have a braille display with  more  than  one  interface,
              e.g. both a serial and a USB port.

       -e (--standard-error)
              Write logs to standard error rather than to the system log (useful for debugging).

       -f file (--configuration-file=)
              The  path  to  the  configuration file.  Relative paths are anchored at the current
              working directory.  The built-in default is /etc/brltty.conf.

       -h (--help)
              Print a command line usage summary (commonly used options only), and then exit.

       -i name (--speech-input=)
              The file system object (FIFO, named pipe, named  socket,  etc)  which  gives  other
              applications  access to brltty's speech driver for text-to-speech conversion.  It's
              created at start-up and removed at termination.  Relative paths are anchored at the
              current  working directory.  The built-in default is that the file system object is
              not created.

       -k table (--keyboard-table=)
              The   path   to   the   keyboard   table.    Relative   paths   are   anchored   at
              /etc/brltty/Keyboard.  The .ktb extension is optional.

       -l level (--log-level=)
              The  minimum  severity level for messages written to the log.  Any of the following
              numbers, or any abbreviation of their corresponding names, may be specified:

              0   emergency

              1   alert

              2   critical

              3   error

              4   warning

              5   notice

              6   information

              7   debug

       The built-in default is notice.

       -m device (--midi-device=)
              The device to use for the Musical Instrument  Digital  Interface.   For  ALSA  it's
              client:port, where each may be either a number or a case-sensitive substring of its
              name.  For other interfaces it's the full path to  an  appropriate  system  device.
              The built-in default is:

              Linux/ALSA  the first available MIDI output port

              Linux/OSS   /dev/sequencer

       -n (--no-daemon)
              Remain in the foreground (useful for debugging).

       -p device (--pcm-device=)
              The device to use for digital audio.  For ALSA it's name[:argument,...].  For other
              interfaces it's the full path  to  an  appropriate  system  device.   The  built-in
              default is:

              FreeBSD     /dev/dsp

              Linux/ALSA  hw:0,0

              Linux/OSS   /dev/dsp

              NetBSD      /dev/audio

              OpenBSD     /dev/audio

              Qnx         the preferred PCM output device

              Solaris     /dev/audio

       -q (--quiet)
              Suppress  the  start-up  messages.   This is done by reducing the default log level
              (see the -l (--log-level=) option) to warning (information if either -v  (--verify)
              or -V (--version) is also specified).

       -r (--release-device)
              Release  the  device  to  which  the  braille display is connected when the current
              screen or window can't be read.

       -s driver,...|auto (--speech-driver=)
              The driver for the speech synthesizer (see  Driver  Specification).   The  built-in
              default is auto.

       -t table (--text-table=)
              The  path to the text table.  Relative paths are anchored at /etc/brltty/Text.  The
              .ttb extension is optional.   The  built-in  default  is  en-nabcc.ttb  (the  North
              American Braille Computer Code).

       -v (--verify)
              Print  the  start-up  messages and then exit.  This always includes the versions of
              brltty itself, the server side of its application programming interface,  and  each
              of  the selected braille and speech drivers.  If the -q (--quiet) option isn't also
              specified then it also includes the values of the options after  all  sources  have
              been  considered.   If  more  than  one braille driver and/or more than one braille
              device has been specified then braille display autodetection is performed.  If more
              than  one speech driver has been specified then speech synthesizer autodetection is
              performed.

       -x driver (--screen-driver=)
              The screen driver.  The built-in default is operating system appropriate.

       -A name=value,... (--api-parameters=)
              Parameters for the application programming interface.  If  the  same  parameter  is
              specified more than once then the rightmost specification is used.  Parameter names
              may be abbreviated.

       -B [driver:]name=value,... (--braille-parameters=)
              Parameters for the braille display driver.  If the same parameter is specified more
              than  once  then  the  rightmost  specification  is  used.   Parameter names may be
              abbreviated.  If a parameter assignment is qualified with a  driver  identification
              code then it's only processed if that braille display driver is being used.

       -D directory (--drivers-directory=)
              The  path  to the directory which contains the dynamically loadable driver objects.
              The built-in default is /lib/brltty.

       -E (--environment-variables)
              Recognize environment variables.

       -F file (--preferences-file=)
              The path to the preferences file.  Relative paths are anchored at  /var/lib/brltty.
              The built-in default is brltty.prefs.

       -H (--full-help)
              Print a command line usage summary (all options), and then exit.

       -I (--install-service)
              (Windows   only)  Install  brltty  as  the  BrlAPI  service  so  that  it  will  be
              automatically started when the system is booted, and so that applications can  know
              that a BrlAPI server is running.

       -K arg (--keyboard-properties=)
              Properties of the keyboard.

       -L file (--log-file=)
              The  file  to  which  log messages are written.  Relative paths are anchored at the
              current working directory.  The default is to send log messages to the system log.

       -M csecs (--message-delay=)
              The message hold time in hundredths of a second.  The built-in default  is  400  (4
              seconds).

       -N (--no-api)
              Don't start the application programming interface.

       -P file (--pid-file=)
              The  full  path to the process identifier file.  If this option is supplied, brltty
              writes its process identifier (pid) into the specified file at start-up.  The  file
              is removed when brltty terminates.

       -R (--remove-service)
              (Windows  only)  Remove the BrlAPI service so that brltty will not be automatically
              started when the system is booted, and so that applications can know that no BrlAPI
              server is running.

       -S [driver:]name=value,... (--speech-parameters=)
              Parameters  for  the speech synthesizer driver.  If the same parameter is specified
              more than once then the rightmost specification is used.  Parameter  names  may  be
              abbreviated.   If  a parameter assignment is qualified with a driver identification
              code then it's only processed if that speech synthesizer driver is being used.

       -T directory (--tables-directory=)
              The path to  the  directory  which  contains  the  text,  attributes,  contraction,
              keyboard, and input tables.  The built-in default is /etc/brltty.

       -U directory (--updatable-directory=)
              The  path  to  a  directory which contains files that can be updated.  The built-in
              default is /var/lib/brltty.

       -V (--version)
              Print the versions of brltty itself, the server side of its application programming
              interface, and those drivers which were configured in at build-time, and then exit.
              If the  -q  (--quiet)  option  isn't  also  specified  then  also  print  copyright
              information.

       -W directory (--writable-directory=)
              The  path  to  a  directory  which  can  be  written  to.   The built-in default is
              /var/run/brltty.

       -X name=value,... (--screen-parameters=)
              Parameters for the screen driver.  If the same parameter  is  specified  more  than
              once then the rightmost specification is used.  Parameter names may be abbreviated.

   Environment Variables
       The  following  environment  variables  are recognized if the -E (--environment-variables)
       option is specified:

       BRLTTY_API_PARAMETERS=name=value,...
              Parameters   for   the   application   programming   interface.    See    the    -A
              (--api-parameters=) option for details.

       BRLTTY_ATTRIBUTES_TABLE=table
              The attributes table.  See the -a (--attributes-table=) option for details.

       BRLTTY_BRAILLE_DEVICE=device,...
              The   device   to   which   the   braille   display   is  connected.   See  the  -d
              (--braille-device=) option for details.

       BRLTTY_BRAILLE_DRIVER=driver,...|auto
              The driver for the braille display.  See  the  -b  (--braille-driver=)  option  for
              details.

       BRLTTY_BRAILLE_PARAMETERS=[driver:]name=value,...
              Parameters  for  the  braille  display  driver.  See the -B (--braille-parameters=)
              option for details.

       BRLTTY_CONFIGURATION_FILE=file
              The configuration file.  See the -f (--configuration-file=) option for details.

       BRLTTY_CONTRACTION_TABLE=table
              The contraction table.  See the -c (--contraction-table=) option for details.

       BRLTTY_MIDI_DEVICE=device
              The device to use for  the  Musical  Instrument  Digital  Interface.   See  the  -m
              (--midi-device=) option for details.

       BRLTTY_PCM_DEVICE=device
              The  device  to  use  for  digital  audio.   See  the -p (--pcm-device=) option for
              details.

       BRLTTY_PREFERENCES_FILE=file
              The preferences file.  See the -F (--preferences-file=) option for details.

       BRLTTY_RELEASE_DEVICE=on|off
              Release the device to which the braille  display  is  connected  when  the  current
              screen or window can't be read.  See the -r (--release-device) option for details.

       BRLTTY_SCREEN_DRIVER=driver
              The screen driver.  See the -x (--screen-driver=) option for details.

       BRLTTY_SCREEN_PARAMETERS=name=value,...
              Parameters  for  the  screen  driver.  See the -X (--screen-parameters=) option for
              details.

       BRLTTY_SPEECH_DRIVER=driver,...|auto
              The driver for the speech synthesizer.  See the -s  (--speech-driver=)  option  for
              details.

       BRLTTY_SPEECH_INPUT=name
              The  file  system  object  which gives other applications access to brltty's speech
              driver for text-to-speech conversion.  See  the  -i  (--speech-input=)  option  for
              details.

       BRLTTY_SPEECH_PARAMETERS=[driver:]name=value,...
              Parameters  for  the  speech synthesizer driver.  See the -S (--speech-parameters=)
              option for details.

       BRLTTY_TEXT_TABLE=table
              The text table.  See the -t (--text-table=) option for details.

   The Configuration File
       Blank lines are ignored.  If the character # occurs on any line then all  characters  from
       it to the end of that line are treated as a comment.

       The following configuration directives are supported:

       api-parameters name=value,...
              Parameters    for    the   application   programming   interface.    See   the   -A
              (--api-parameters=) option for details.

       attributes-table table
              The attributes table.  See the -a (--attributes-table=) option for details.

       braille-device device,...
              The  device  to  which  the   braille   display   is   connected.    See   the   -d
              (--braille-device=) option for details.

       braille-driver driver,...|auto
              The  driver  for  the  braille  display.  See the -b (--braille-driver=) option for
              details.

       braille-parameters [driver:]name=value,...
              Parameters for the braille display  driver.   See  the  -B  (--braille-parameters=)
              option for details.

       contraction-table table
              The contraction table.  See the -c (--contraction-table=) option for details.

       midi-device device
              The  device  to  use  for  the  Musical  Instrument  Digital Interface.  See the -m
              (--midi-device=) option for details.

       pcm-device device
              The device to use for  digital  audio.   See  the  -p  (--pcm-device=)  option  for
              details.

       preferences-file file
              The preferences file.  See the -F (--preferences-file=) option for details.

       release-device on|off
              Release  the  device  to  which  the  braille display is connected when the current
              screen or window can't be read.  See the -r (--release-device) option for details.

       screen-driver driver
              The screen driver.  See the -x (--screen-driver=) option for details.

       screen-parameters name=value,...
              Parameters for the screen driver.  See the  -X  (--screen-parameters=)  option  for
              details.

       speech-driver driver,...|auto
              The  driver  for  the speech synthesizer.  See the -s (--speech-driver=) option for
              details.

       speech-input 0me
              The file system object which gives other applications  access  to  brltty's  speech
              driver  for  text-to-speech  conversion.   See  the -i (--speech-input=) option for
              details.

       speech-parameters [driver:]name=value,...
              Parameters for the speech synthesizer driver.  See  the  -S  (--speech-parameters=)
              option for details.

       text-table table
              The text table.  See the -t (--text-table=) option for details.

   Driver Specification
       A  braille  display  or speech synthesizer driver must be specified via its identification
       code:

              al  Alva

              an  Android

              at  Albatross

              ba  BrlAPI

              bc  BrailComm

              bd  Braudi

              bg  B2G

              bl  BrailleLite

              bm  Baum

              bn  BrailleNote

              cb  CombiBraille

              ec  EcoBraille

              es  eSpeak

              eu  EuroBraille

              fl  FestivalLite

              fs  FreedomScientific

              fv  Festival

              gs  GenericSay

              hd  Hedo

              hm  HIMS

              ht  HandyTech

              hw  HumanWare

              ir  Iris

              ic  Inceptor

              lb  Libbraille

              lt  LogText

              mb  MultiBraille

              md  MDV

              mm  BrailleMemo

              mn  MiniBraille

              mp  Mikropuhe

              mt  Metec

              no  no driver

              np  NinePoint

              pg  Pegasus

              pm  Papenmeier

              sd  SpeechDispatcher

              sk  Seika

              sw  Swift

              th  Theta

              tn  TechniBraille Systems Inc.

              ts  Telesensory Systems Inc.

              tt  TTY

              vd  VideoBraille

              vo  Voyager, Part232 (serial adapter), BraillePen/EasyLink

              vr  Virtual

              vs  VisioBraille

              vv  ViaVoice

              xs  ExternalSpeech

              xw  XWindow

              A comma-delimited list  of  drivers  may  be  specified.   If  this  is  done  then
              autodetection  is  performed using each listed driver in sequence.  You may need to
              experiment in order to  determine  the  most  reliable  order  since  some  drivers
              autodetect better than others.

              If  the  single  word  auto is specified then autodetection is performed using only
              those drivers which are known to be reliable for this purpose.

SEE ALSO

       For      full      documentation,      see      brltty's      on-line      manual       at
       [http://brltty.com/documentation.html].