hhfilter: 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/hhfilter - from package: hhsuite

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

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