how to run a program in the background and get the standard output

[turboman]

Hello, everyone.
My question may not be very much relevant to FOX. But I use fox for my code integration.

I want to use fox to make some GUI for my fortran programs.
These programs have some input files and are usually run in the command line ( I work on linux machines).

What I want to do is to crreate a GUI for these programs, so that I can run a program by clicking a button, at the same time, I want to get the standard screen output and put it in something, probably,FXText.

I use the function of system to run the program, but I do not know how to get the output once the program is running. I also hope the output can be updated as the program is run in a command line.

Any comment will be appreciated.

Turboman.