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From: toad@CS.CMU.EDU (Todd Kaufmann)
Newsgroups: comp.lang.perl
Subject: non-blocking streams/rsh emulator  (receptionist/client example)
Message-ID: <TOAD.91Mar27014611@ZEN.MT.CS.CMU.EDU>
Date: 27 Mar 91 06:46:11 GMT
Sender: toad@ZEN.MT.CS.CMU.EDU
Distribution: comp
Organization: School of Computer Science, Carnegie Mellon University
Lines: 35

On most machines here in cs.cmu.edu we are running Mach, which don't
usually have rsh (but of course perl runs on everything!).  I've been
playing with the receptionish & client examples from the camel book, but if
the line doesn't have a newline after it, it isn't flushed.

Simple example "demon" script:

  #!/bin/csh -f
  # test non-blocking io
  set flag=1
  while ($flag)
    echo -n "prompt> "
    set ans=$<
    if ("$ans" == "q") set flag=0
    echo Did you say $ans \?
  end
  exit 0

the problem is that the prompt isn't seen until a line has been entered
(and then you see the previous prompt).  I've tried (trial-n-error) to put
in an ioctl call in receptionist (add CBREAK - wrong?), but that didn't
seem to do it.  rsh and telnet do this.. how?

What am I doing wrong?  

Eventually I'd like to add passing sigint & sigquit to the remote end.
Does anyone have that?


.. oh yeah, I'm using perl 3.0, patch level 41.     (and what about wait3?)

thanks a bunch,
   Todd Kaufmann
   Center for Machine Translation
   CMU     412/ 268-7130