funhead: 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 Debian possible default full paths are:

/usr/bin/funhead - from package: funtools

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

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