showkey: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/showkey - from package: kbd

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/showkey - from package: kbd

You may install the required package with command apt-get install {package}

Error in other languages:
showkey: bevel nie gevind nie
showkey: comandă negăsită
showkey: comando não encontrado
showkey: commande introuvable
showkey: command not found
showkey: käsku ei ole
showkey: không tìm thấy lệnh
showkey: komanda nerasta
showkey: Kommando nicht gefunden.
showkey: kommandot finns inte
showkey: komut yok
showkey: nie znaleziono polecenia
showkey: níor aimsíodh an t-ordú
showkey: no se encontró la orden
showkey: no s'ha trobat l'ordre
showkey: opdracht niet gevonden
showkey: parancs nem található
showkey: perintah tidak ditemukan
showkey: príkaz nenájdený
showkey: příkaz nenalezen
showkey: команда не найдена
showkey: командата не е открита
showkey: 命令找不到
showkey: コマンドが見つかりません