dfbfx: 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 CentOS possible default full paths are:

/usr/bin/dfbfx - from package: directfb

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

On Debian possible default full paths are:

/usr/bin/dfbfx - from package: libdirectfb-bin

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