po_names: 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/bin/po_names - from package: polyorb-servers

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

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