curator: 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/curator - from package: elastic-curator

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

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