ufo: 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/lib64/parrot/3.3.0/languages/perl6/bin/ufo - from package: rakudo-star

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

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