brltty

BRLTTY(1)                     The BRLTTY Project                     BRLTTY(1)



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 translation table.  Relative paths
              are anchored at /etc/brltty/.  The .tbl extension is optional.
              The built-in default is attributes.tbl.

       -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/.  The .ctb extension is optional.

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

              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 bluez: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:/path/to/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:
                     serial:/dev/, serial:, /dev/, .

              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 interrface, 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 and then exit.

       -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 translation table.  Relative paths are
              anchored at /etc/brltty/.  The .tbl extension is optional.  For
              a simple file name, the text.  prefix is optional.  The built-in
              default is text.nabcc.tbl (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.

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

       -F fifo (--speech-fifo=)
              The FIFO which gives other applications access to brltty's
              speech driver.  It's created at start-up and removed at
              termination.  Relative paths are anchored at /etc/brltty/.  The
              built-in default is that no FIFO is created.

       -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.

       -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.

       -U csecs (--update-interval=)
              The braille window update interval in hundredths of a second.
              The built-in default is 4 (25 times per second).

       -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.

       -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 translation 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_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_FIFO=fifo
              The FIFO which gives other applications access to brltty's
              speech driver.  See the -F (--speech-fifo=) 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 translation 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 translation 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.

       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-fifo fifo
              The FIFO which gives other applications access to brltty's
              speech driver.  See the -F (--speech-fifo=) 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 translation 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

              at  Albatross

              ba  BrlAPI

              bd  Braudi

              bl  BrailleLite

              bm  Baum

              bn  BrailleNote

              bs  BrailleSense

              cb  CombiBraille

              ec  EcoBraille

              es  ExternalSpeech

              eu  EuroBraille

              fl  FestivalLite

              fs  FreedomScientific

              fv  Festival

              gs  GenericSay

              ht  HandyTech

              il  IrisLinux

              lb  Libbraille

              lt  LogText

              mb  MultiBraille

              md  MDV

              mn  MiniBraille

              mp  Mikropuhe

              no  no driver

              pm  Papenmeier

              sd  SpeechDispatcher

              sw  Swift

              th  Theta

              tn  TechniBraille Systems Inc.

              ts  Telesensory Systems Inc.

              tt  TTY

              vd  VideoBraille

              vo  Voyager

              vr  Virtual

              vs  VisioBraille

              vv  ViaVoice

              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://mielke.cc/brltty/doc/Manual-HTML/Manual.html].



brltty 3.10                        July 2008                         BRLTTY(1)