poddiff: 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/poddiff - from package: sdf

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

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