po2php: 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/po2php - from package: translate-toolkit

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

On Debian possible default full paths are:

/usr/bin/po2php - from package: translate-toolkit

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

Error in other languages:
po2php: bevel nie gevind nie
po2php: comandă negăsită
po2php: comando não encontrado
po2php: commande introuvable
po2php: command not found
po2php: käsku ei ole
po2php: không tìm thấy lệnh
po2php: komanda nerasta
po2php: Kommando nicht gefunden.
po2php: kommandot finns inte
po2php: komut yok
po2php: nie znaleziono polecenia
po2php: níor aimsíodh an t-ordú
po2php: no se encontró la orden
po2php: no s'ha trobat l'ordre
po2php: opdracht niet gevonden
po2php: parancs nem található
po2php: perintah tidak ditemukan
po2php: príkaz nenájdený
po2php: příkaz nenalezen
po2php: команда не найдена
po2php: командата не е открита
po2php: 命令找不到
po2php: コマンドが見つかりません