From: "ara.t.howard" <ara.t.howard@...>
Date: 2007-06-06T05:04:48+09:00
Subject: Re: Problems with IO.popen in ruby 1.8.2?


On Jun 5, 2007, at 1:02 PM, Todd A. Jacobs wrote:

> I have the following code snippet:
>
>     sleep 0.3
>     IO.popen('/usr/bin/xclip -o').readlines {|f| print}
>
> running in a tight loop. If I let it run for a short time (about 25
> seconds), I get this error:
>
>     Enter URL: ./dice.rb:89:in `popen': Too many open files - /usr/ 
> bin/xclip -o (Errno::EMFILE)
> 	    from ./dice.rb:89:in `read'
> 	    from ./dice.rb:181
> 	    from ./dice.rb:162:in `loop'
> 	    from ./dice.rb:162
>
> I don't understand the nature of the error, since the pipe is  
> implicitly
> closed when the block exits, right? Event if I change the line to:
>
>     IO.popen('/usr/bin/xclip -o').readlines {|f| print; f.close}
>
> I still have the same problem. So, what file resource is being  
> consumed,
> and how do I fix it?

read carefully - you've given the block to readlines - not popen.   
invert your logic

	IO.popen(cmd) do |pipe|
           pipe.readlines{|line| print line}
         end


>
> -- 
> "Oh, look: rocks!"
> 	-- Doctor Who, "Destiny of the Daleks"
>

-a
--
we can deny everything, except that we have the possibility of being  
better. simply reflect on that.
h.h. the 14th dalai lama