tupi: 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/tupi - from package: tupi
/usr/lib/tupi/bin/tupi - from package: tupi

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

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