ptbl: 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/ptbl - from package: snacc

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

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