btdownloadcurses.bittornado: command not found

Have You tried accessing the binary with the full path?

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/btdownloadcurses.bittornado - from package: bittornado

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