atst: 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/atst - from package: scotch

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

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