Question about 4.2BSD uprintf()

[Chris Torek]

In article <559 at stride.stride.UUCP> bruce at stride.UUCP (Bruce Robertson)
writes:

> The comments for the function uprintf() advertise that you can
> call it from an interrupt routine to send a message to the
> current user's terminal.  [But] uprintf() will print its message
> on the terminal of the *currently running* process.

Right you are.

> I can't think of any situation where you would want to actually
> call uprintf() from an interrupt routine.

Messages like `no write ring', while they do not really belong in
the kernel, are useful; these can be done by noting the lack of a
write ring in some per-device data structure, and having the device
open routine do the uprintf() as well as returning an error.  (Some
tape drives do not have write lock as a status bit: you must ask.)
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 1415)
UUCP:	seismo!umcp-cs!chris
CSNet:	chris at umcp-cs		ARPA:	chris at mimsy.umd.edu