yodl: 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/yodl - from package: yodl

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

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