How do you catch user input while the script is running?
Or, how would you make two scripts run at the same time, but use input from one script to the other?

The program I'm trying to make, echos text on the screen continuously, but while thats happening, I want the user to be able to input something, so the program can detect the input and display something else. So I thought maybe I could make two scripts run to do each task. Can anyone solve my problem?

I think this a case for a more advanced language than the bash scripting language. For me it seems to be a perfect case for a language that have bindings to the ncurses library, so that you can have different input and output areas on the screen. Maybe Python, Ruby or something similar.

Have you looked at the talk command? it may be what your looking for?

talk is a chat program, I don't see the point why you recommend it here.

I haven't used talk, but assuming it's a terminal-based chat program, I imagine it was suggested as a reference--some code to look at. The OP said he wanted to get user input and simultaneously stream text to the screen. So, at a basic level, a terminal-based chat program would accomplish what the OP wants.

That said, I imagine talk is not written in a scripted language, but rather a compiled one. So, it may not be a very useful reference.

Your two script idea can be made to work. The simplest way to accomplish your objective might be to have the "echo" program periodically check for the existence of some file, and the "read" program create the file when the input is read. The '"echo" program would, of course, delete the file after it processed it. (You could even use the file to pass information from the "read" program to the "echo" program.)

Look at man test for various file existence directives. Note also the sleepcommand that you can use so your test loop won't "eat" all your CPU cycles.

You might also want to look at pipes that can be used to connect separate processes. If you aren't restricted to using bash, you might find the discussion (and implementation) of bi-direction pipes in gawk interesting. (Note that bi-directional pipe is a gawk extension, not available in standard (POSIX) awk.)