I have a PHP system that calls a "process B" with a very long execution, so I intend to use shell_exec("caminho/da/pasta/sistema_externo parametros"); so it runs in the background, ie another PHP process calls the file and executes, leaving "free" the web system. This call loads an entire system behind it and it can not stay in the% Apache root folder%.
How to execute the script in isolation, without allowing a user to execute the command but the system can freely achieve?