Can outsiders get simple questions answered?

Dan Hensley
Wed Dec 30 18:32:00 GMT 1998


Christopher Faylor wrote:

> On Wed, Dec 30, 1998 at 02:24:19PM -0700, Dan Hensley wrote:
> >But it still looks like tcsetattr isn't able to set all of my
> >attributes correctly, namely:
> >
> >iflag: ICRNL
> >cflag: CREAD
> Neither of these is implemented by Cygwin.

Do you know if there are any plans to implement these in the future?

> >I'm also finding some other strange behavior:
> >* When I set both serial port and keyboard for polling by select, and I
> >enter something via serial port, it FD_ISSET() correctly tells me that
> >the serial port had the input.  However, read() locks up my bash
> >session (or at least won't return control--I can still type) when I try
> >to read the buffer after serial port input.  I believe this may be due
> >to ICRNL not being set.  Any thoughts?
> Since Cygwin doesn't currently do anything but raw reads on the serial
> port, you're probably seeing a wait while your buffer fills up.  You
> can work around this by doing one byte reads or by playing with VMIN
> or VTIME although neither of those is fully implemented either.

I'll take a look at that and see what I can come up with.

> >* When I set both serial port and keyboard for polling by select, and I
> >enter something via the keyboard, FD_ISSET() tells me that both the
> >keyboard and the serial port had input.
> My test case doesn't show this.  Sorry.

Hmmm... That's weird.  I'll take a closer look at the fd_set structure and
the macro and see if I can see why this is happening.  The workaround is
simple enough in the code, but I'd like to understand what's happening.
Would you like my source code for debugging/testcase purposes (it's changed
a little from the original I sent)?


Dan Hensley
Engineer - SDRC Operations (ATA)
Denver, CO        W:303/464-7049

For help on using this list (especially unsubscribing), send a message to
"" with one line of text: "help".

More information about the Cygwin mailing list