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Subject: Re: Filtering Everything
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Date: Tue, 14-Apr-87 03:22:20 EST
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Posted: Tue Apr 14 03:22:20 1987
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> Can't you use them just like ptty's?

No, you can't.  That's the whole point.  Think of an "sxt" as an
8-position switch connecting one physical terminal to up to 8 virtual
ones.  Data coming from the physical terminal is routed to the input
queue of one of the 8 virtual terminals.  Data written to any of the
virtual virtual terminals is routed to the output queue of the
physical terminal, unless the virtual terminal in question isn't the
current one and LOBLK is set on that virtual termnal in which case
the "write" blocks until the virtual terminal becomes the current
one.

There's no place here to plug in a user process so that it sees the
data flying by; the whole point of a pseudo-tty is to plug a user
process into the data stream.