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This article introduces the knowledge of "how socket simulates sending http requests". Many people will encounter this dilemma in the operation of actual cases, so let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!

Socket simulates sending a http request

As we all know, osi has a seven-tier model, but our TCP/IP protocol does not fully conform to this model. But there are some things that have both, so let's talk briefly about the transport layer and the application layer.

We know that this transport layer is the TCP and UTP protocols, while the application layer is the HTTP, SMTP, FTP and other protocols that we often use. Those protocols in the application layer are based on the transport layer protocols and are encapsulated in order to achieve specific functions. So everyone is going to ask, what is this socket and where is it? Look down:

Originally here, Socket is the intermediate software abstraction layer for communication between the application layer and the transport layer (TCP/IP protocol family). We can think of it as a set of interfaces (api). In the design pattern, Socket is actually a facade pattern, which hides the complex TCP/IP protocol family behind the Socket interface. For users, a simple set of interfaces is all, allowing Socket to organize the data to comply with the specified protocol. We can use Socket to simulate HTTP requests so as to achieve the purpose of pseudo-HTTP protocol.

We take the get way to request Baidu home page as an example, using Socket to simulate sending HTTP requests.

We can directly imitate the request header information of the browser to send the request. Of course, we can modify the url through the urlparse method provided by urllib, and then send the information by passing parameters. The relevant code is as follows:

# / usr/bin/python

#-*-coding:utf-8-*-

# @ author: Envse

# @ file: socket_http.py

# @ time: 16:06 on 2018-10-03

# requests-- > urllib-- > socket

Import socket

From urllib.parse import urlparse

Def get_url (url):

# request Url through socket

Url = urlparse (url)

Host = url.netloc

Path = url.path

If path = "":

Path = "/"

# establish a socket connection

Client = socket.socket (socket.AF_INET, socket.SOCK_STREAM)

Client.connect (host, 80))

Client.send ("GET {} HTTP/1.1\ r\ nHost: {}\ r\ nConnection:close\ r\ n\ n\ n" .format (path, host) .encode ('utf8')) # relative path

Data = b ""

While True:

D = client.recv (1024)

If d:

Data + = d

Else:

Break

Data = data.decode ('utf8')

Html_data = data.split ("\ r\ n\ r\ n") [1]

Print (html_data)

Client.close ()

If _ _ name__ = ='_ _ main__':

Get_url ("http://www.baidu.com/")"

This code is actually easy to understand, which simulates the client to send a request to the server. First of all, we need to use the get_url method to process the simulated url, then establish a socket connection, send the content, and finally receive the response content and output it, and close the connection. Running result:

Let's take a look at the source code of Baidu's home page viewed through the browser. Is it about the same?

That's all for "how socket simulates sending http requests". Thank you for reading. If you want to know more about the industry, you can follow the website, the editor will output more high-quality practical articles for you!

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