tthsplit: 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/tthsplit - from package: tth-common

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

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