Such pipemill may not perform as intended if the body of the loop includes commands, such as codice_9 and codice_10, that read from codice_11: on the loop's first iteration, such a program (let's call it "the drain") will read the remaining output from codice_12, and the loop will then terminate (with results depending on the specifics of the drain). There are a couple of possible ways to avoid this behavior. First, some drains support an option to disable reading from codice_11 (e.g. codice_14). Alternatively, if the drain does not "need" to read any input from codice_11 to do something useful, it can be given codice_16 as input.