[SOLVED]Ruby Popen3.open3 system command got stuck

Problem:

In Ruby, Open3.popen3 is a good way to execute a system command and get the output of the command. Following is the a piece of code that does this.


Open3.popen3(*cmd) do |stdin, stdout, stderr, wait_thread|
      err = stderr.gets
      out = stdout.gets
      [stdin, stdout, stderr].each{|stream| stream.send('close')}
      exit_status = wait_thread.value
end

It works well when your command throws some error to stderr. However, it got stuck forever if your command executes successfully without any error message, BECAUSE err=stderr.gets GOT STUCK.

Solution:

READ stdout FRIST