turtleart: 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/turtleart - from package: turtleart

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

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