ffbblog: 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/ffbblog - from package: fawkes-plugin-bblogger

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

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