pac: 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/sbin/pac - from package: lpr

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

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