rfdir: 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 CentOS possible default full paths are:

/usr/bin/rfdir - from package: dpm

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/rfdir - from package: dpm

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

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