ruby小例子-動態執行，綁定，線程

#encoding:utf-8# ---------動態執行#執行2 + 2puts eval "2 + 2"#=》4#執行15 * 2 （Q表示雙引號會進行運算，q表示單引號會原樣輸出）number = 15code = %Q{#{number} * 2}puts codeputs eval(code)#=》4#=》#{number} * 2# ---------綁定def binding_test  return bindingendbinding_function = binding_testx = 9eval("x = 10")eval("x = 50", binding_function)#處理當前環境的局部變數eval("puts x")#處理binding環境的局部變數eval("puts x", binding_function)#exec "data.rb"#puts "end"#ruby的線程不是由作業系統來提供，由ruby解譯器來執行#優點：跨平台效能很好#缺點：如果需要叫用作業系統並等待回應，則整個ruby程式就會暫停#新開線程child = fork do  sleep 1  puts "child ok"endputs "waiting for child process"Process.wait childputs "end"#線程#建立10個線程隨機睡眠，列印 threads = []10.times do  thread = Thread.new do    10.times {|i|       print i      $stdout.flush      #轉讓線程執行權      Thread.pass      sleep 1      }  end  threads <<threadendputs Thread.list.inspect#join讓主線程等待至線程執行完畢threads.each() do |thread|  thread.join(3)end