loofah-update: 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/loofah-update - from package: python-loofah

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

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