SHOWKEY(1)                                                                                                            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 inter-
       nal 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 personal-
       ized 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.soft-
       raw=0 that tells the 2.6 kernel to return the actual scan codes.


NOTES
       The raw scan codes are available only on AT and PS/2 keyboards, and even then they are disabled  unless  the  atkbd.soft-
       raw=0  kernel  parameter  is  used.  When the raw scan codes are not available, the kernel uses a fixed built-in table to
       produce scan codes from keycodes.  Thus, setkeycodes(8) can affect the output of showkey in scan code dump mode.


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



                                                           1 Feb 1998                                                 SHOWKEY(1)