pdnsd-ctl: 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/sbin/pdnsd-ctl - from package: pdnsd

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

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