用C/ c++读写屏幕处理

I was wondering how one might connect to a screen process in C/C++, I often want to have a C program listen to the output to that screen window and react to that output as well as send some input to the program running on that session. I am just unsure as to how I'm supposed to connect to that screen session and I haven't found anything very useful doing my searches.I was wondering how one might connect to a scre