From: hargrove@theory.TC.Cornell.EDU (Paul H. Hargrove) Subject: working on FIFOs for Linux 0.96 Date: Fri, 22 May 1992 06:47:46 GMT
I have just finished my first attemp at kernel programming, and I do
believe that it has been a success. I _THINK__ that I have implemented
simple FIFOs in the 0.96 kernel. The big question that remains is how
EXACTLY are FIFOs to behave with respect to read(), write(), and select().
That is, according to POSIX, when should read() and write() block, and
when should they return 0, or EAGAIN. As far as select() goes, I need
to know what is defined as an exeption on a FIFO (readers but no writers,
writers but no readers, or either of these two?)
Also what should stat() return for the size field. I would guess zero, but
that information is not useful, so maybe POSIX wants something that a
programmer could use like the number of bytes in the buffer, or something
like that.
NOTE:
If anyone has already done fifo special files for Linux, and I'm wasting
my time, please let me know. I'm doing it as a learing experience, so I'd
love to have someone else's work to compare mine to.
-- Paul H. Hargrove hargrove@theory.tc.cornell.edu "A witty saying proves nothing." --Voltaire