htdump: 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/htdump - from package: htdig

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

On Debian possible default full paths are:

/usr/bin/htdump - from package: htdig

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

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