说明：  简要介绍一下什么是Linux，C语言的特点，程序开发的预备知识，Linux下C语言开发的环境，程序设计的特点和原则以及编码风格等。通过本章的学习，可以对在Linux下使用C语言编程有一个基本的了解。
(A brief overview of what is Linux, C language features, prior knowledge of program development, Linux development environment under the C language, program design features and principles of coding style. By studying this chapter, you can use the C language in Linux have a basic understanding of programming.)