Bug with readFile and named pipes

[Volker Stolz]

In local.glasgow-haskell-bugs, you wrote:
> Programs that read from a named pipe usually block until a writer opens 
> the pipe and writes something to it. The following program,
> 
>     main = putStr =<< readFile "/tmp/p"
> 
> (where "/tmp/p" refers to a named pipe) exhibits this behavour when 
> compiled with HBC or when run with runhugs, but *not* when compiled with 
> GHC. Instead the program immediately exists, returning the empty string.

I don't know if we`re talking about different things, but when I
played around with fifos (e.g. For TCP/Hugs :-), I noticed that it is
recommended to open the FIFO for *writing* *before* *opening* it for
*reading*, even if you`re not going to write to it yourself.

I wouldn`t want readFile opening my file for writing under normal cases,
so I'd recommend you use a hack which opens the file for writing first.

One could imagine that readFile tests the filetype  and does
The Right Thing(TM), but I`m not sure I want that, either.
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