STREAMS tty drivers for SysV

[Leslie Mikesell]

In article <45 at calcite.UUCP> vjs at calcite.UUCP (Vernon Schryver) writes:

>It is impossible to put a SVID-compliant tty under the SVR3.[012] stream head
>as it comes on the 3B2 source tapes.  There is no provision for VTIM/VMIN in
>the SVR3 streams head, and you cannot do it below the head in SVR3 streams.
>Also, the SVR3 stream head believes a non-blocking read returns EAGAIN like
>BSD ttys and other, reasonable SV devices, instead of 0 like SVID tty's.

AT&T 3B2's with Starlan have a streams based tty emulation for logging in
over the net, and it does show exactly the problems you mention.  The
most common trouble is with programs that don't check for a negative return
from read() after setting O_NDELAY (and why should they?).

Les Mikesell