tth: 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/tth - from package: tth

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

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