Python 3 Programming Tutorial - Threaded port scanner

Now that we've seen how to make a simple port scanner in Python 3, we've found that it is quite slow and cumbersome. So here, we tie in our knowledge of the threading module that we learned previously to dramatically improve our performance.

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[empiresodemember]

Awesome videos! I really like Python as a language in its whole and these videos have helped me understand a lot of those intermediate programming concepts/features in Python that are sometimes difficult to work with/understand. I hope you post more often! Thanks for all the help!

[MorganFreemanIsLife]

Ports 1 through 1024 are reserved for system protocols on a your computer. That's why you only had two ports showing up as open.

[FreeER]

sentdex 
Do you realize that s.connect() does not actually return a connection (or any other) object? The close method is defined on the socket itself. so it should be s.close(), alternatively you could use the with statement eg. with s: s.connect((server, port))

P.S. it seems like you should close the socket prior to attempting to acquire the print_lock considering that it blocking could cause a delay in releasing the socket. Though probably an entirely unnecessary observation considering the number of available sockets and the low chance of the block being for any significant amount of time.

P.P.S. Glad I found your videos :)

[huffypufty]

Hi . I love ur videos . Mostly. I got problem with this port scanner . It took almost 1 day to complete .

[WalterBurkholder]

let's say I wanted to have a queue of threads for multiple definitions to run in, just waiting on standby. and when a definition is ran it grabs a unused thread, so not to interrupt another definition in the middle of running. then when nothing is running, your threads are on stand by again. basically how do I make your threader definition more dynamic, so I can throw a function at it instead of hard coding the function into it?

[anandachakraborti]

Great tutorial! Can you do a series on how to talk to a node.js back-end with python?

[NetPwn]

Quick question, if you were to implement this as a module the first thing to call would be the for x in range(whatever range ) -- > t.start() section of the code right? so in essence starting the domino effect.

[MrCatinthehat]

Love your videos, man. Can you explain how the pet scanner actually 'learns' that the port is open? IE: is it using SYN/SYN ACK? or something different?

[niprjct]

How can we get the scanner to read from a list fo targets of a file?

[mafiaboy]

i got up the point of test my port in windows. bij i got the following problem.
Traceback (most recent call last):
File "C:\Ronny\Netwerken\sever2.py", line 25, in <module>
main()
File "C:\Ronny\Netwerken\sever2.py", line 8, in main
s.bind((host, port))
OSError: [WinError 10048] Elk socketadres (protocol/netwerkadres/poort) kan normaal slechts één keer worden gebruikt.

Ques.: how can i get around this???

[kostasklimantakis]

Hi! in this specific example port 80 should always be open right?

[bean]

import sys
...
target = input("Enter URL or IP: ")

[fairytail]

Great job. I haven't looked up on ports yet, but it appears you have port 22 and 80 up on your site, and google has only 80 up

[computerscientist]

I don't understand, why this port scanner will scan for open ports? Could you explain a bit why connecting to a random web-site reveals open ports?

[kapilverma]

How does multiplayer games find game hosts so fast?

[californiaesnuestra]

Great tutorial!. (Dog distraction 6:28) 

[yunuskaya]

i realy like your videos they're great, you look like snowden btw

[matanlll]

bro im not sure i totally get what Queue means ..
like the thing i dont get is how the are the threads know like whom shold take which port
i tried my own version with out Queue [ coz as i was saying i didnt comprehend it and im not just gonna copy ur code..]
and what i did was deviding the number of ports with the number of threads but and there is ..
they dont run linearly .. i mean i[ it works but its not like 1, 2, 3, 4, 5, ]
coz one thread is going from 1-20 and another from 20-40

[slashahood]

how do i kill the thread after it's done scanning (python 3.8)? i ran this code, and it stayed stuck with an active thread infinitely

[multigladiator]

Whats the differen between socket.SOCK_STREAM and DGRAM?