cardpeek: 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 Debian possible default full paths are:

/usr/bin/cardpeek - from package: cardpeek

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

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