I've been fiddling with the "maplay" audio MPEG player this afternoon, and ran
into 2 oddities:

(1) It does the following:

  if ((fd = open ("/dev/audio", O_WRONLY | O_NDELAY, 0)) < 0)
...
  // turn NDELAY mode off:
  int flags;
  if ((flags = fcntl (fd, F_GETFL, 0)) < 0)
...
  flags &= ~O_NDELAY;
  if (fcntl (fd, F_SETFL, flags) < 0)
  {
    perror ("fcntl F_SETFL on /dev/audio failed");
    exit (1);
  }
...

    The fcntl(fd, F_GETFL, 0) is returning "5".  But the subsequent F_SETFL
    fails.  <fcntl.h> shows that "FNONBLOCK" (== O_NONBLOCK, as is O_NDELAY)
    is in FCNTLFLAGS as an allowable settable bit for F_SETFL.  So I wonder
    why this is failing?  Come to think of it, if I comment out the twiddling
    of the "flags", it still fails.  Hmmn ...

(2) If I don't this ioctl(), the program works but generates a lot of errors
    because of the write()'s returning EAGAIN.  I've ported other stuff like
    the MBone IVS tool with a similar output mechanism yet I don't get the
    same type of errors with IVS (or VAT, for that matter; I get the occasional
    "audio write: Operation would block", but nowhere near the amount I get
    with "maplay").  Hmmn again ...

I suspect the 2nd problem might be alleviated by the 1st, if I knew why the
fcntl() was failing.  Any ideas?  Any NetBSD/SPARC audiophiles around?  :-)

	- Greg