基于MD5的文件完整性检测程序，共包含4个文件：md5.h、md5.cpp、test.cpp、nankai.txt。其中md5.h与md5.cpp文件实现了md5类。test.cpp文件包含了整个程序的main函数，根据不同的命令完成不同的功能，如显示摘要信息，生成MD5摘要等。nankai.txt是本书提供的用于验证文件完整性测试文件。读者可以自己编写程序来生成nankai.txt的md5摘要，然后与书中的结果进行比较，验证所编程序的正确性。

编译：命令行模式下，切换到代码所在目录，输入make后回车即可。

运行：在命令行下输入 ./md5 [-参数] 运行程序。根据不同的功能，参数分为五种类型，功能如下：

h是帮助信息

t是测试MD5应用程序

c是计算指定文件的MD5值

mv是手动验证指定文件的完整性

fv是通过.md5文件验证指定文件的完整性-MD5-based file integrity testing procedures, contains four files: md5.h, md5.cpp, test.cpp, nankai.txt. Which implements md5.h md5 file with md5.cpp class. test.cpp file contains the main function of the entire program, perform different functions depending on the command, such as display summary information, generate MD5 digest. nankai.txt the book provides file integrity verification test files used. Readers can write your own program to generate md5 summary nankai.txt then be compared with the results of the book, to verify the correctness of compiled programs. Compile: command line mode, switch to the code directory, enter make press Enter. Run: At the command line, type ./md5 [- arguments] to run the program. Divided into five types, the following functions depending on the functions, parameters:. H is help t test MD5 application c is calculated MD5 value of the specified file mv fv manually verify the integrity of the specified file is specified by md5 file validation file integr