self_pipe_into_pager.rb

def pipe_to_pager(pager = "less")
  r, w = IO.pipe

  if fork
    # parent
    $stdin.reopen(r)
    w.close
    exec pager
  else
    # child
    r.close
    $stdout.reopen(w)
  end
end

if $stdout.tty?
  pipe_to_pager
end