The solution to that issue was given by the use of background
processes. The main PHP script will execute the run of another
script using the ‘‘exec’’ command of the Linux environment.
A new process will be initiated in the background and its id will
be stored. Then through the application’s webpage the user can
view all the launched processes and can monitor the time left to
complete their procedure, stop the scripts or remove them from
the list (Fig. 5). At any point only one process is active and the
others are pending till they become active, to avoid overload
of the server.