pp: 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/pp - from package: libpar-packer-perl

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

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