detect_ppa: 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/detect_ppa - from package: pnm2ppa

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

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