pscan: 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/pscan - from package: pscan

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

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