macunpack: 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/macunpack - from package: macutils

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