The following line of code works fine:
           ioctl(fd, FIOASYNC, 0);
   Where fd is a file descriptor returned from a call to socket(). However,
   the following piece of code:
           ioctl(fd, FIOASYNC, 1);
   returns -1 with errno set to EFAULT.

You're supposed to make the third argument a *pointer*.  Something like:

int one = 1;
ioctl(fd, FIOASYNC, &one);

I'm not sure why it would work at all with a null pointer.  Perhaps
you're misinterpreting.


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