loook: 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/loook - from package: loook

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

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