htdbm: 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/htdbm - from package: httpd-tools

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

On Debian possible default full paths are:

/usr/bin/htdbm - from package: apache2-utils

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

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