with_stdin (pipe to gets.chomp)

with_stdin.rb

# credit http://stackoverflow.com/a/16950202/2949493

  def with_stdin
    stdin = $stdin             # remember $stdin
    $stdin, write = IO.pipe    # create pipe assigning its "read end" to $stdin
    yield write                # pass pipe's "write end" to block
  ensure
    write.close                # close pipe
    $stdin = stdin             # restore $stdin
  end
  
# usage:
# with_stdin { |stdin| stdin.puts "text"; gets.chomp }
# which will return: "text"

# Note the "return" word cannot be used in the block

# It turns out this was not the solution i was looking for. Instead, I'm using Shell
  require "shell"
    sh = Shell.new
    result = (sh.system("echo exit") | sh.system("irb")).to_s