Question

Sorry if this seems like a dumb question but I am just learning bash scripting. For a school project we need to code an RTX that runs in Unix. It runs as a process in terminal and takes in user input and then prints it to the screen. I want to write a bash script to test that it can respond to lots of quick user input without overflowing or failing.

My main problem is that once the RTX starts the bash script will stop on that line until the RTX terminates and only then print the loop to the terminal (instead of printing it to the RTX prompt as I intend it to).

I have tried running the RTX in the background but that didn’t work. I need to find a way to redirect input to the RTX while it is still running with a bash script. Google searches didn’t come up with examples that I understood/could adapt. Any help is appreciated.

#!/bin/bash
# declare STRING variable
STRING="RTX Worked =D"
#Start the rtx in a new process, stuck on this line until rtx terminates. 
./main
#Somehow redirect io to the rtx. 
    for i in `seq 1 100`;
    do
            echo $i 
    echo " \n"
    done    
echo $STRING

Answer 1

You can run co-processes in bash and then send commands to the co-process via a pipe.

see the Bash Manual under the coproc subcommand

Its been a while since I did it and I’ve lost my examples but something like

coproc RTX ./main

for i in 'seq 1 100`;
do
     echo $i >&{RTX[1]}
done