rpdb2: 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/rpdb2 - from package: winpdb

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

On Debian possible default full paths are:

/usr/bin/rpdb2 - from package: winpdb

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

Error in other languages:
rpdb2: bevel nie gevind nie
rpdb2: comandă negăsită
rpdb2: comando não encontrado
rpdb2: commande introuvable
rpdb2: command not found
rpdb2: käsku ei ole
rpdb2: không tìm thấy lệnh
rpdb2: komanda nerasta
rpdb2: Kommando nicht gefunden.
rpdb2: kommandot finns inte
rpdb2: komut yok
rpdb2: nie znaleziono polecenia
rpdb2: níor aimsíodh an t-ordú
rpdb2: no se encontró la orden
rpdb2: no s'ha trobat l'ordre
rpdb2: opdracht niet gevonden
rpdb2: parancs nem található
rpdb2: perintah tidak ditemukan
rpdb2: príkaz nenájdený
rpdb2: příkaz nenalezen
rpdb2: команда не найдена
rpdb2: командата не е открита
rpdb2: 命令找不到
rpdb2: コマンドが見つかりません