showkey(1)

NAME

   showkey - examine the codes sent by the keyboard

SYNOPSIS

   showkey [-h|--help] [-a|--ascii] [-s|--scancodes] [-k|--keycodes]

DESCRIPTION

   showkey  prints to standard output either the scan codes or the keycode
   or the `ascii' code of each key pressed.  In the first  two  modes  the
   program  runs until 10 seconds have elapsed since the last key press or
   release event, or until it receives a suitable  signal,  like  SIGTERM,
   from  another process.  In `ascii' mode the program terminates when the
   user types ^D.

   When in scancode dump mode, showkey prints in hexadecimal  format  each
   byte  received  from the keyboard to the standard output. A new line is
   printed when an interval of about 0.1 seconds occurs between the  bytes
   received,  or  when  the  internal receive buffer fills up. This can be
   used to determine roughly, what byte sequences the  keyboard  sends  at
   once  on  a  given  key  press. The scan code dumping mode is primarily
   intended  for  debugging  the  keyboard  driver  or  other  low   level
   interfaces.  As  such  it  shouldn't be of much interest to the regular
   end-user. However, some modern keyboards  have  keys  or  buttons  that
   produce  scancodes  to  which  the kernel does not associate a keycode,
   and, after finding out what these are, the  user  can  assign  keycodes
   with setkeycodes(8).

   When  in  the default keycode dump mode, showkey prints to the standard
   output the keycode number or each key pressed or released. The kind  of
   the  event,  press  or release, is also reported.  Keycodes are numbers
   assigned by the kernel to each individual physical key. Every  key  has
   always  only  one associated keycode number, whether the keyboard sends
   single or multiple scan codes when pressing it. Using showkey  in  this
   mode,  you can find out what numbers to use in your personalized keymap
   files.

   When in `ascii' dump mode, showkey prints to the  standard  output  the
   decimal,  octal, and hexadecimal value(s) of the key pressed, according
   to he present keymap.

OPTIONS

   -h --help
          showkey prints to the standard error output its version  number,
          a compile option and a short usage message, then exits.

   -s --scancodes
          Starts showkey in scan code dump mode.

   -k --keycodes
          Starts  showkey  in keycode dump mode. This is the default, when
          no command line options are present.

   -a --ascii
          Starts showkey in `ascii' dump mode.

2.6 KERNELS

   In 2.6 kernels key codes lie in the range 1-255, instead of 1-127.  Key
   codes  larger  than  127  are  returned as three bytes of which the low
   order 7 bits are: zero, bits 13-7, and bits 6-0 of the key  code.   The
   high order bits are: 0/1 for make/break, 1, 1.

   In  2.6  kernels  raw  mode,  or scancode mode, is not very raw at all.
   Scan codes are first translated to key codes, and  when  scancodes  are
   desired, the key codes are translated back. Various transformations are
   involved, and there is no  guarantee  at  all  that  the  final  result
   corresponds  to what the keyboard hardware did send. So, if you want to
   know the scan codes sent by various keys it is better  to  boot  a  2.4
   kernel.  Since 2.6.9 there also is the boot option atkbd.softraw=0 that
   tells the 2.6 kernel to return the actual scan codes.

SEE ALSO

   loadkeys(1), dumpkeys(1), keymaps(5), setkeycodes(8)

                              1 Feb 1998                        SHOWKEY(1)

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Free and Open Source Software