title: writing to stdin of another program/reading from stdout of another program in c
body: <p>It's a homework question. I have  3 programs A, B and C, they are not father/child processes, but separate programs.  B must write a message ("Hello") to the stdin of A and read another message ("Hello") from stdout of C. Which concept i should use to implement it? I looked around for some time but i couldn't find anything proper. I thought i should use FIFO, but i couldn't redirect pipes. Can i use dup2 with FIFO? if yes, how? It's not the homework's itself, it just the way it should work. Then I will implement other things on it. (I can post my fifo base code, if it's the case, just don't do it now because i'm not sure)</p>