说明：  CMake是一个跨平台的安装（编译）工具，可以用简单的语句来描述所有平台的安装(编译过程)。新版本的cmake可能和老版本的cmake有区别，特此找到了老版本的2.8.1来分享
(CMake is a cross platform installation (compilation) tool that describes the installation (compilation process) of all platforms with a simple statement. The new version of cmake may be different from the older version of cmake, so I've found the old version of 2.8.1 to share)