gencfu: 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/gencfu - from package: icu

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

On Debian possible default full paths are:

/usr/bin/gencfu - from package: icu-devtools

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

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