Shell Script Multithreaing

To run multiple programs in parallel:
prog1 &
prog2 &

If you need your script to wait for the programs to finish, you can add:
wait

prog1 & prog2 && fg
This will:
1>Start prog1.
2>Send it to background, but keep printing its output.
3>Start prog2, and keep it in foreground, so you can close it with ctrl-c.
4>When you close prog2, you'll return to prog1's foreground, so you can also close it with ctrl-c.
Sharath2172