showkey(1)



SHOWKEY(1)                  General Commands Manual                 SHOWKEY(1)

NAME
       showkey - examine the codes sent by the keyboard

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

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 inter-
       faces. 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 setkey-
       codes(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.

       -V --version
              showkey prints version number and exits.

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 corre-
       sponds 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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