fprint_demo: 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/fprint_demo - from package: fprint-demo

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

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