diodcat: 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/sbin/diodcat - from package: diod

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

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