Manual: showkey

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	 un‐
       til  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.

       -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 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.

AUTHORS
       Andries Brouwer 

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

kbd							 1 Feb 1998						  SHOWKEY(1)