hercules: 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/hercules - from package: hercules

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

On Debian possible default full paths are:

/usr/bin/hercules - from package: hercules

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

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