ratmenu: 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/ratmenu - from package: ratmenu

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

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