dvbsnoop: 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/dvbsnoop - from package: dvbsnoop

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

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