fghack: 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/fghack - from package: daemontools

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

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