named pipes

[Albert Y. C. Lai]

Main.hs does not open fromA at all. (fromA_IO is dead code.) This causes 
fifo2.c to be hung whenever it opens fromA. From the man page of 
mkfifo(3) on Linux:

"Opening a FIFO for reading normally blocks until some other process 
opens the same FIFO for writing, and vice versa. See fifo(7) for 
nonblocking handling of FIFO special files."

In the sister thread in haskell-cafe, the addition of unsafePerformIO 
throws further disorder into these highly order-sensitive operations.