I would like the output of A to be input for B and at the same time the output of B to be the input for A, is that possible? I tried the naïve thing: creating named pipes for A (pipeA) and B (pipeB) and then: pipeB | A | pipeA & pipeA | B | pipeB & But that does not work (pipeB is empty and switching the order would not help either). …