rpmextra.pl: 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/rpmextra.pl - from package: rpmorphan

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

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