rpmconf: 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/sbin/rpmconf - from package: rpmconf

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

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