I have a trivial question. How can I use user's input as an URL in a Python app with socket libraries?

I have this code:

import socket

mysock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
mysock.connect(('data.pr4e.org', 80))
cmd = 'GET http://data.pr4e.org/romeo.txt HTTP/1.0\r\n\r\n'.encode()
mysock.send(cmd)

while True:
    data = mysock.recv(512)
    if len(data) < 1:
        break
    print(data.decode(),end='')

mysock.close()

And now I'm supposed to change it so that the app opens an URL provided by the user, not the one which is now hard-coded. I've tried many things, all of 'em fail with a different error message.

The things I tried: 1)

url = input("Enter URL: ")
[...]
cmd = 'GET url HTTP/1.0\r\n\r\n'.encode()
mysock.send(cmd)

Then I tried separating my url variable from the rest of the line with commas:

cmd = 'GET', url, 'HTTP/1.0\r\n\r\n'.encode()

I also tried to be creative:

url = input("Enter URL: ")
realurl = "GET"   " "   url   " "   "HTTP/1.0\r\n\r\n'.encode()"
[...]
cmd = realurl
mysock.send(cmd)

For the sake of simplicity, let's now skip the problem with mysock.connect's content - I was trying to launch the app with a link to page on the same host.

CodePudding user response：

cmd = 'GET http://data.pr4e.org/romeo.txt HTTP/1.0\r\n\r\n'.encode()

should be

cmd = 'GET /romeo.txt HTTP/1.0\r\n\r\n'.encode()

domain shouldnt be included in the path...add a host header which has http://data.pr4e.org/ as the value....

CodePudding user response：

If you had printed the cmd then your issue would be rather clear. Formatting was incorrect and .encode()needs to be applied to the entire concatenated string!

1. cmd = 'GET url HTTP/1.0\r\n\r\n'.encode() is a bytes like obj that doesn't include the actual url

2. cmd = 'GET', url, 'HTTP/1.0\r\n\r\n'.encode() is a tuple (str, str, bytes)

3. realurl = "GET" " " url " " "HTTP/1.0\r\n\r\n'.encode()" is a string that contains a string .encode() rather than applying it to the str.

url = input("Enter Url: ")`
cmd = 'GET '   url   ' HTTP/1.0\r\n\r\n'
# Encode encodes a string to a bites like obj.
# Therefore we must apply it to the entire string!
mysock.send(cmd.encode())