From: Ben Giddings <bg-rubytalk@...>
Date: 2004-06-14T02:15:20+09:00
Subject: Re: oddities with select (do we need .to_bool?)

On Jun 12, 2004, at 23:23, Chris Reay wrote:
> I replied to this a moment ago, and then did the ad hoc experiment
> that I should have done before opening my virtual mouth earlier -
> sorry 'bout that.

No worries, sorry for implying you might be trolling.  I thought that 
my earlier example made it clear how the 'if' statement in Ruby works, 
but I guess the truth table was even more clear.

> I tested this:
>
> require "socket"
>
> svr = TCPServer.new("localhost", 4567)
> sock = svr.accept
> printf "Accepted conn\n"
> while true
>   if select([sock], [], [], 3.0)
>     printf("%s\n", sock.recv(256))
>   end
> end
>
> I sent some "hello world" messages to it from a TCPSocket. It works
> perfectly.
>
> Sorry to appear tardy, tedious or trollish; but what gives?

My question exactly.  For me, it works -- *most* of the time.  But 
sometimes, especially when I send it only a single newline, that 
newline just isn't seen.  Select returns nil, but ethereal shows that a 
packet has arrived.  Hence my original question -- why isn't select() 
seeing that newline.

I guess the correct thing to do is rewrite the thing in C and see if 
it's a problem in the OS or if it's a problem in Ruby.

Ben