proc与sys文件系统，proc编程

https://blog.csdn.net/Qiuoooooo/article/details/76977307

//proc编程
https://www.jianshu.com/p/73a100666591
https://blog.csdn.net/wangshuchangfrank/article/details/22853639
https://blog.csdn.net/askbai666888/article/details/7914570