Anyone understand SXT's (Sys V)

[Russell Brown]

Does anyone understand how the sxt mechanisms work on Sys V.{2,3} ? I have the
sxt(7) man entry which tells me something but not enough. I also have the
shl(1) utility which works in it's own fashion but again doesn't give the 
game away.

I understand how to open /dev/sxt/??0 and fire up the multiplexing with
the ioctls specified in sxt(7). Whats really got me though is how the
controlling process (ie shl) knows that I've thumped the ^Z key and should
pop back into life.

In time honoured tradition I've RTFM'd and grovelled through /usr/include/*.h
to no avail. I cannot seem to find any answers. 

Any help/clues would be greatly appreciated.

Many thanks.
	Russell
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| Russell Brown                        | Voice: +44 832 72224             |
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