whirlpooldeep: 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/whirlpooldeep - from package: md5deep

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

On Debian possible default full paths are:

/usr/bin/whirlpooldeep - from package: md5deep

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

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