From: ara.t.howard@...
Date: 2006-06-26T22:45:02+09:00
Subject: Re: Blocking read after select

On Mon, 26 Jun 2006, Antonin AMAND wrote:

> Hi,
>
> I've some trouble reading an IO after a select

you are calling IO#read, which reads till eof.  try something like

   buf = rsock.read 8192

and you should see data.  typically one would have the client do somthing like

   bufsize = [buf.size].pack 'N'
   s.write bufsize
   s.write buf
   s.flush

and, in the server, something like

   bufsize = s.read 4
   bufsize = bufsize.unpack('N').first
   buf = s.read bufsize

in otherwords, every message is preceded by it's length in a packet guarunteed
to be 4 bytes big.  you might start out with something like this (untested):

   class NetString < ::String
     def self.recv io
       buf = io.read 4
       size = buf.unpack('N').first
       new(read(size))
     end

     def self.send s, io
       s = s.to_s
       size = [s.size].pack('N')
       io.write size
       io.write s
     end

     def send io
       self.class.send self, io
     end
   end

then you can do

   ns = NetString.recv socket

or

   ns = NetString.new 'foobar'
   ns.send socket

regards.

-a
-- 
suffering increases your inner strength.  also, the wishing for suffering
makes the suffering disappear.
- h.h. the 14th dali lama