子调用exec（）后使用pipe（）

My end goal is to have a parent process pass lines of text to the child, then the child process will print the text to stdout. The child is to run "permanently" in the back ground while the parent gets user input and pass's it to the child. I prefer the child in a separate program. Differentiating between child and paretn through if statements is messy as fudge. My end goal is to have a parent process pass li