sac: 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/sac - from package: sac

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

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