woof: 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/woof - from package: woof

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

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