From: Hugh Sasse <hgs@...>
Date: 2005-10-14T00:33:05+09:00
Subject: Re: exec and pipe

On Fri, 14 Oct 2005, ientu wrote:

> Hi All,
> 
> I have been coding-testing-googling all day long but I couldn't find a
> solution for this.
> I need to create a pipe between some ruby code and a perl script. The
> perl script  will be the writer: the script prints on STDOUT lines of
> information at a random pace.
> These lines are to be processed in ruby in real time, as soon as they
> enter the pipe, without waiting for the termination of the perl script.
> 
> Another requirement is that the perl script must be invoked from a ruby
> class.
> 
> I have tried with the following:
> 
> readme, writeme = IO.pipe
> pid = fork {
>   $stdout = writeme
>   readme.close
>   exec('perl some_script.pl')

I think you want IO.popen for this.  Two examples that worked for
me:
http://www.eng.cse.dmu.ac.uk/~hgs/ruby/html_spell.rb
http://www.eng.cse.dmu.ac.uk/~hgs/ruby/top.rb

        Hugh