wrudf: 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/wrudf - from package: udftools

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

On Debian possible default full paths are:

/usr/bin/wrudf - from package: udftools

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

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