Not a typewriter

[Kenneth Almquist]

> If a read or write is interrupted by a signal, it will return 0 or
> number of bytes written before the interrupt occured.  In this case
> errno = 4, and no error code is returned from the system call.

I suspect you are misreading the documentation.  When a write system
call is interrupted, it may either return a short count or return -1.
Errno is set to 4 in the latter case.  I don't know of any version of
UNIX in which read will return zero when interrupted.
				Kenneth Almquist