cdfpsi_level: 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/cdfpsi_level - from package: cdftools

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

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