From: Ara.T.Howard@...
Date: 2005-05-14T03:55:28+09:00
Subject: Re: Get back data from a child (with exec)

On Fri, 13 May 2005, Lawrence Oluyede wrote:

> Ara.T.Howard@noaa.gov writes:
>
>>    harp:~ > cat a.rb
>>    IO::popen('-') do |pipe|
>>      if pipe
>>        stdout = pipe.read
>>        puts "parent got <#{ stdout }> from child"
>>      else
>>        exec 'echo', '-n', '42'
>>      end
>>    end
>>
>>    harp:~ > ruby a.rb
>>    parent got <42> from child
>
> Works, but there's a problem. If I open the pipe in read/write mode and exec
> a program that reads from stdin it doesn't work :(

   harp:~ > cat a.rb
   IO::popen('-', 'r+') do |pipe|
     if pipe
       pipe.puts '42'
       pipe.close_write
       stdout = pipe.read.strip
       #pipe.close
       puts "parent got <#{ stdout }> from child"
     else
       exec 'cat'
     end
   end

   harp:~ > ruby a.rb
   parent got <42> from child


you aren't trying to run a program that requires a tty (like top) are you?

-a
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