说明：  C语言作的图书管理系统 该程序能实现对一本书进行采编入库、清除库存、借阅图书、归还图书且记录借书的用户信息，还有查找书、显示图书目录的功能，并且以该书的书号为关键字建立一个B_树。
(C language does books management system management system this procedure can realize to a book carries on picks enrolls the storehouse, the elimination stock, borrows the books, returns the books also the record borrows the book the user information, but also has the search book, the demonstration library catalog function, and establishes a B_ tree take this book book number as the essential character. )