Re: non-block reading from pipe stdout

[kdevel via Digitalmars-d-learn]

On Tuesday, 3 October 2017 at 12:20:09 UTC, Oleg B wrote:
        while (!tryWait(pp.pid).terminated)
        {
            auto cnt = read(fd, buf.ptr, buf.length); // 
C-style reading
            if (cnt == -1 && errno == EAGAIN) // C-style error 
checking
                yield();
            else if (cnt > 0)
            {
                doSomething(buf[0..cnt]);
                yield();
            }
        }

IMHO a program should sleep (consume 0 CPU time and 0 energy) if 
there is nothing to process. This is best accomplished by not 
polling on a file descriptor in order to check if data has 
arrived. If your program must yield() there's probably something 
wrong with the design. I would suggest you put all the 
filedescriptors into a fd_set an then select(3) on the set.