安徽理工大学计算机科学和工程学院.pptVIP

Outline What is GNU? The GNU operating system is a complete free software system, upward-compatible with Unix. GNU stands for “GNUs Not Unix”. Richard Stallman made the Initial Announcement of the GNU Project in September 1983. Source: /gnu/initial-announcement.html What is Free Software? “Free software” is a matter of liberty, not price. To understand the concept, you should think of “free” as in “free speech”, not as in “free beer”. Free software is a matter of the users freedom to run, copy, distribute, study, change and improve the software. More precisely, it refers to four kinds of freedom, for the users of the software: The freedom to run the program, for any purpose (freedom 0). The freedom to study how the program works, and adapt it to your needs (freedom 1). Access to the source code is a precondition for this. The freedom to redistribute copies so you can help your neighbor (freedom 2). The freedom to improve the program, and release your improvements to the public, so that the whole community benefits (freedom 3). Access to the source code is a precondition for this. What is gcc? GCC, the GNU Compiler Collection. The GNU Compiler Collection includes front ends for C, C++, Objective-C, Fortran, Java, and Ada, as well as libraries for these languages (libstdc++, libgcj,...). GCC was originally written as the compiler for the GNU operating system. The GNU system was developed to be 100% free software, free in the sense that it respects the users freedom. Source: 2.1 GNU C/C++编译器的使用 2.1 GNU C/C++编译器的使用 2.1 GNU C/C++编译器的使用 Linux上广泛使用的C语言编译器是GNU C编译器，GNU C建立在自由软件基金会的编程许可证的基础上，可以自由发布。在Linux下，一个完整的C语言开发环境到少包括以下三个组成部分： 函数库glibc (在/usr/lib和/lib目录中) 编译器gcc 系统头文件glibc_header (*.h) glibc是构成一个完整的C语言开发环境所必不可少的组成部分，也是Linux下C语言的主要函数库。 glibc_header中包含了系统编译源代码所需要的声明文件,如果缺少系统头文件，很多用到系统功能的C程序将无法编译。(包含在/usr/include/及其子目录中) 2.2 GNU C/C++函数库 定义：是一些预先编译好的函数的集合，那些函数都是按照可再使用的原则编写的。它们通常是一组相互关联的用来完成某项常见工作的函数构成（比如c库里面的标准输入输出函数、时间函数和数学函数等）。 函数库中的函数可以通过连接程序与应用程序进行连接，而不必在每次