说明：  本章介绍了 C 语言的一些基本信息，这些信息对处理 FLUENT 的 UDF 很有帮助。本章首先假定你有一些编程经验而不是 C 语言的初级介绍。本章不会介绍诸如 while-do 循环，联合，递归，结构以及读写文件的基础知识。如果你对 C语言不熟悉可以参阅 C 语言的相关书籍。
(This chapter introduces some basic information of C language, which is very helpful to handle UDF of FLUENT. This chapter first assumes that you have some programming experience rather than a preliminary introduction to C language. This chapter does not cover the basics of while-do loops, unions, recursions, structures, and reading and writing files. If you are not familiar with the C language, you can refer to the related books in C language.)