snooper: 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/snooper - from package: snooper

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

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