4.2 BSD Signals: A Proposal
tjt at kobold.UUCP
tjt at kobold.UUCP
Mon Jan 16 06:46:54 AEST 1984
Actually, this is a follow-on to:
Also, it has always bothered me that the terminal driver in 4.1 made it
necessary to do as many as 4 ioctls in order to do logically-connected
things. That was a compatibility move too... Of course, this change
doesn't using the new semantics clumsy.
This was actually somewhat inherited from V7; the System III/System V handler
cleans this up, although if 4.3BSD or whatever picked up the USG tty driver
and then re-Berkeleyized it they might have to introduce a second "ioctl" to
turn on the local flags and supply the local control characters, which would
bring us back to where we started from...
If you "re-Berkeleyize" the USG tty driver, any additional ioctl should
work in the spirit of the USG ioctl's, and let you set *all* the flag
words/special characters with a single ioctl. I thought part of the
reason for all them ioctl's in the 4BSD tty driver (actually from
IIASA) was leftover from V6 days when the stty/gtty entry point was
passed *exactly* three int's (or six char's) from user space, and this
was carried over as a superstition.
--
Tom Teixeira, Massachusetts Computer Corporation. Westford MA
...!{ihnp4,harpo,decvax}!masscomp!tjt (617) 692-6200 x275
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