Windows Serial Ports

Frank Baumgart
Fri Apr 10 15:30:00 GMT 1998

Geoffrey Noer wrote:

> > Has anyone tried talking to the serial ports under gnuwin32?

> You should be able to just open "comn" where n is a number from 1 to 4
> and then communicate with it normally...


read() does not work (blocks in non-blocking mode)
select() does not work (returns even if no data is available)
alarm() does not interrupt within a read() call
open() does not set non-blocking mode on serial devices

(see <> also)

This is not quite what I would call "normally", more like "making
workarounds difficult to impossible" leaving few choices:

1) try further workarounds, hoping that FIONREAD or poll() might work
   (does not look too promising though)
2) use the WIN32 API (d'lng dox right now)
3) fix cygwin32 myself. Apart from having neither knowledge nor 
   experience with the WIN32 API so far, few knowledge about cygwin32, 
   I am not the one who debugs the debugger to develop his application.
   More like the GPLed application programmer who wants to port an 
   application to Win32 and cares about his "customers" complaints
4) complain about it here. Well, maybe it helps or another guy more
   capable and willing to fix this runs into the same problem ;-)
   Of course I am willing to assist with detailed bug and trace reports.

Has anybody been successful in porting some kind of getty on serial 

Best regards,


P.S.: I like cygwin32 and have been able to port my own GPLed apps 
apart from the most important one which depends on a working serial
communication layer/emulation
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