1.http://www.runoob.com/linux/linux-shell.html
2.http://blog.sina.com.cn/s/blog_4152a9f501013r6c.html
3.http://blog.csdn.net/df0128/article/details/44097659
4.http://blog.csdn.net/lionfire/article/details/6634254
5.基于 shell 脚本的 Android 启动时间测试:https://testerhome.com/topics/4763
