tthprep: 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/tthprep - from package: tth-common

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

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