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。-MD5 File Integrity based detection program, contains a total of 4 files: md5.h, md5.cpp, test.cpp, nankai.txt. Which md5.h achieved with md5.cpp file md5 class. test.cpp file contains the main function of the program, according to the different commands perform different functions, such as display summary information, generate MD5 summaries. nankai.txt is the book used to verify file integrity provided by the test file. Readers can write your own program to generate the md5 nankai.txt summary, and then compare the results with the book to verify the correctness of compiled programs.