From: Xeno Campanoli <xcampanoli@...>
Date: 2008-05-31T06:37:11+09:00
Subject: Re: getting standard error and output from ruby script in real time

Stefano Crocco wrote:
> I'm trying to write an editor for ruby in ruby using the KDE4 bindings for 
> ruby and I'm facing a problem which I don't know whether is caused by ruby or 
> by KDE. I want my editor to be able to run a ruby script and display both the 
> error messages and the normal output in a window. The problem is that all the 
> text sent to the standard output seems to be received together from my 
> application, and so does the text sent to standard error, even if the two are 
> mixed. For example, when I run the following script
> 
> 5.times do |i|
>   warn "Warning #{i}"
>   puts i
> end
> 
> the output window of my program displays this:
> Warning 0
> Warning 1
> Warning 2
> Warning 3
> Warning 4
> 0
> 1
> 2
> 3
> 4
> 
> instead of this (which is what I get if I run the script from terminal)
> Warning 0
> 0
> Warning 1
> 1
> Warning 2
> 2
> Warning 3
> 3
> Warning 4
> 4
> 
> Since I don't have much experience on interprocess communication, I can't, as 
> I said, understand if this issue is due to the way ruby prints its output or 
> to the tools I use to run the ruby script from my editor, which are specific 
> of KDE. I'd be glad if someone could give me a hint on this, so that at least 
> I can know whether I have to look for documentation about ruby or about KDE.
> 
> Thanks in advance
> 
> Stefano
> 
> 
STDERR.puts
puts is stdout.