brew/Library/Homebrew/utils/popen.rb

module Utils
  def self.popen_read(*args, &block)
    popen(args, "rb", &block)
  end

  def self.popen_write(*args, &block)
    popen(args, "wb", &block)
  end

  def self.popen(args, mode)
    IO.popen("-", mode) do |pipe|
      if pipe
        return pipe.read unless block_given?
        yield pipe
      else
        $stderr.reopen("/dev/null", "w")
        exec(*args)
      end
    end
  end
end