说明：  介绍在 LINUX 下进行 C 语言编程所需要的基础知识：进程、文件操作、时间操作、时间概念、信号处理、消息管理、线程操作、网络编程等等
(Describes the C language programming under LINUX required basic knowledge: process, file operations, operating time, time concepts, signal processing, information management, thread operations, network programming, etc.)