编写漏洞扫描器探查远程服务器上可能存在的具有安全隐患的文件是否存在，它的socket建立过程和上面 的端口扫描器是相同的，所不同的是漏洞扫描器通常使用80端口，然后对这个端口发送一个GET文件的请求，服务器接收到请求会返回文件内容，如果文件不存 在则返回一个错误提示，通过接收返回内容可以判断文件是否存在。发送和接收数据需要使用函数send()和recv()，另外对流中存在的字符串进行判断 需要使用函数strstr()，这除了需要具备socket函数库的知识以外，还需要一些有关string函数库的知识。-The preparation of vulnerability scanners detect a remote server that may exist with the security risks of the file exists, and its socket to establish the process and above the port scanner is the same, the difference is that vulnerability scanners typically use port 80, and then on the port send a GET request for the document, the server receives the request will return the contents of the documents, if the file does not exist then return an error message, through the receiver can determine whether to return to the contents of the file exists. Send and receive data need to use the function send () and recv (), exists in another string convection judge need to use the function strstr (), which apart from the need to have the socket library of knowledge, also need some string library知识.