On Thu, Jan 07, 1999 at 06:42:21PM +0000, Glynn Clements wrote:
>
> Michele Bini wrote:
>
> > How can it be? select() returns 1 (as if fd 0 had
> > some data pending, but read() returns 0 and doesn't
> > read any byte)
>
> When read() returns 0 it is indicating EOF.
>
> Note that select() doesn't indicate that data is available: it
> indicates that calling read() on the descriptor won't block.
The manpage doesn't seem to say so:
Three independent sets of descriptors are watched. Those
listed in readfds will be watched to see if characters
become available for reading, those in writefds will be
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
watched to see if it is ok to immediately write on them,
and those in exceptfds will be watched for exceptions. On
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
exit, the sets are modified in place to indicate which
descriptors actually changed status.
If EOF is an exception I would expect to be noticed only if I
put fd 0 in the exceptfds set.
-Michele
