HTTP agreement ： Hypertext transfer protocol
Dumb server , Connect to the server without typing HTTP Of 8 An order , The server will not respond to any information . And the average server , Such as FTP, After connecting, there will be a welcome message .HTTP After the server is connected , There will be no welcome messages , Will not take the initiative to say hello to you .
command ： nc www.126.com 80
After returning , The server is connected , But the server didn't return any information .
Then enter the command ： GET /
（ obtain HTTP The root file of the server ）
The next part is the server's return information .
without GET request , Then the server will not return any information . This is the dumb server .
One ＵＲＬ（ Uniform resource locator ） It's made up of three parts （ agreement , host （host）,URI（ Uniform resource identifiers ））
Such as ＵＲＬ：
among ,http Is agreement ,www.hikvision.com Host computer , /cn/news_det_85_i208.html yes URI.
Whole Request package , Except for the first line , The rest are Header
HTTP It's an instantaneous protocol , That is to say, after getting the data , Close connection .
Cookie, It's to let the intermittent HTTP agreement , It looks like continuous . At the first request , Server to client settings Cookie, And keep the... On the server Cookie A span ; For subsequent requests , All clients carry this Cookie. It is usually used to verify whether users log in or not .
Use netcat Command to get the request directly from the simulated browser .
Obtain by command HEAD. Note that HTTP/1.0
OPTIONS command . Notice, too HTTP/1.0.