dh_pdl: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH

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/bin/dh_pdl - from package: pdl

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