carettah: 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/carettah - from package: carettah

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

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