dat2s: 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/dat2s - from package: liballegro4-dev

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

Error in other languages:
dat2s: bevel nie gevind nie
dat2s: comandă negăsită
dat2s: comando não encontrado
dat2s: commande introuvable
dat2s: command not found
dat2s: käsku ei ole
dat2s: không tìm thấy lệnh
dat2s: komanda nerasta
dat2s: Kommando nicht gefunden.
dat2s: kommandot finns inte
dat2s: komut yok
dat2s: nie znaleziono polecenia
dat2s: níor aimsíodh an t-ordú
dat2s: no se encontró la orden
dat2s: no s'ha trobat l'ordre
dat2s: opdracht niet gevonden
dat2s: parancs nem található
dat2s: perintah tidak ditemukan
dat2s: príkaz nenájdený
dat2s: příkaz nenalezen
dat2s: команда не найдена
dat2s: командата не е открита
dat2s: 命令找不到
dat2s: コマンドが見つかりません