atsar: command not found

Have You tried accessing the binary with the full path?

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/atsar - from package: atsar

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