ffinfo: 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/ffinfo - from package: fawkes-core

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

On Debian possible default full paths are:

/usr/lib/voxbo/bin/ffinfo - from package: voxbo

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

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