From: Walton Hoops <me@...>
Date: 2011-02-15T03:06:14+09:00
Subject: Re: Reading/writing to spawned process

On 2/12/2011 6:03 PM, Joel F. wrote:
> Hi,
>
> I'd like to spawn a process, then write some stuff to it, then read from
> stuff from it, then write more, then read more, etc etc.  (Ruby 1.9 and
> Windows)
>
> The way that I've done this is something like:
>
> ------------------------------
> require 'open3'
> require 'io/wait'
>
> input, output, err = Open3.popen3('cmd')
> input.puts 'echo hi'
> output.read(output.stat.size)
> input.puts 'echo bye'
> output.read(output.stat.size)
> -------------------------------
>
> This seems mostly okay, but I have a couple questions.
>
> 1. In IO/wait, there's a method called "ready?".  If I call "ready?" in
> this program, it returns false even when stat.size indicates that there
> actually IS in fact data to be read.  I'm having trouble understanding
> it.
> 2. In IO/wait, there's a method called "nread".  However, if I call
> output.methods.sort, it's not there and I cant use it.  I see "ready?"
> and "wait", but no "nread".
That's odd, when I try on 1.9.2 on Windows, there is no ready?, wait, or 
nread methods, though they all show a class of IO.  My Ruby:
C:\Users\walton.hoops>ruby --version
ruby 1.9.2p136 (2010-12-25) [i386-mingw32]

When I get home I'll try to remember to test on Linux.  It could be an 
OS specific thing.
> 3. I'm sure I'm not the first bozo to complain about the
> documentation...but the primary documentation for ruby's standard
> libraries (ruby-doc.org) is pretty sucky.  I'm just feeling frustrated
> atm.  It took me a lot of hours to come up with the little code that I
> have>_<.  Is there an alternative site that has more meaningful
> documentation?
No, your not. Personally I recommend rdoc.info over ruby-doc.org.  It is 
the same documentation, but in my opinion it's much better organized.
> I just signed up for the ruby documentation mailing list so I can make
> some suggestions...but is there maybe an easier way?  It would be nice
> if there was just some form that I could fill out and say "on this page
> it says X, but it would be more helpful if it said Y".  Or even a wiki
> version of the API.
Not that I am aware of.  Actually the best way to get these kinds of 
changes through would be to clone the repository and submit a 
documentation patch.

Hope that helps some

Walton