From: David Miller <dmiller@...>
Date: 2009-06-27T15:37:41+09:00
Subject: question about IO.select

Hello all

I was looking at some code in a textmate bundle support library that
wasn't working for me.  (I am using e text editor on a XP machine)  The
problem appears to be that IO.select is returning a value that I believe
means that data is available to be read, however there does not seem to
be any data available.  I have read what I can find about this, but I
don't understand the result I am seeing.

If I run demo code below, IO.select returns immediately.  data[0]
contains $stdin, but there are no characters in the stdin buffer so the
getc blocks waiting for input.  If I enter several characters and hit
return, the first two characters will show up in the two  data[0].getc
statements.

In this example I thought the IO.select would wait for up to 20 seconds
for characters to be available, and return a nil at that time if none
were.

This is a XP box running 1.8.6

What am I missing?

Thanks

Dave M




data, x, x  = IO.select([$stdin], nil, nil, 20.0)

puts "$stdin.to_s returns: #{$stdin.to_s}"
puts "$data[0].to_s returns: #{data[0].to_s}"

puts "data[0].getc.to_s returns: #{data[0].getc.chr}"
puts "data[0].getc.to_s returns: #{data[0].getc.chr}"
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