Streams yet again

David Herron, NPR Lover david at ukma.UUCP
Fri Jan 31 01:31:02 AEST 1986


Here I am debugging yet another script for dialing a modem.  This time
it's for PhoneNet.  (Oh, if anybody has one for use with Hayes compatible
modems...)  But I'm wishing I had something like "tee" that I could
stick between the process and the real device.  So I could really and
truly SEE what's going on, rather than trust the phonenet program to
tell me all that's going on.  (It might be missing some of it).

So it occurs that streams could be used to do this in the same way that
Ritchie has implemented TCP/IP.  He has a /dev entry for the network
device (i.e. /dev/deuna0..).  Then a set of protocols are pushed on top
of the device and packets from each protocol appear on other /dev things.

I can see two useful ways of doing what I want.

1) send all input and output to one device, marking it in some way
   at to whether it's input or output.
2) send input to one other device, output to yet another device.
   This leads naturally to a split screen monitoring program...

No, I don't think this could be effectively used for eavesdropping.
You'd have to arrange this beforehand, and have super-user privs to
begin with.  On the other hand... it's another way of doing script(1).
(Or can it?)


Yours for a better designed Unix.  (Will it be called "Unix++"?)

-- 
David Herron,  cbosgd!ukma!david, david at UKMA.BITNET, soon, david at uky.csnet.

Experience is something you don't get until just after you need it.



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