BermudanSwaption: 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/BermudanSwaption - from package: quantlib-examples

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

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