Port-Scanner-in-Python

Overview In this project, you’ll build a simple port scanner that checks a range of TCP ports on a target system to identify which ones are open. This project uses Python’s built-in socket module to attempt connections and will introduce you to basic network communication.

Software Pyhton Visual Code Studio

Create the Python Script File Creation: Create a new file named port_scanner.py.

3. Write the Code Copy and paste the following code into your file: import socket import sys

def scan_ports(target, start_port, end_port): """ Scans a range of TCP ports on the specified target to check if they are open.

Parameters:
    target (str): Target hostname or IP address.
    start_port (int): Starting port number.
    end_port (int): Ending port number.
"""
# Resolve the target's hostname to an IP address
try:
    target_ip = socket.gethostbyname(target)
except socket.gaierror:
    print("Error: Unable to resolve hostname.")
    sys.exit()

print(f"Scanning {target} ({target_ip}) from port {start_port} to {end_port}:\n")

for port in range(start_port, end_port + 1):
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    socket.setdefaulttimeout(1)  # Set a timeout of 1 second for each connection attempt
    result = s.connect_ex((target_ip, port))
    if result == 0:
        print(f"Port {port}: Open")
    s.close()

if name == 'main': # Get target and port range from the user target = input("Enter the target hostname or IP address: ") try: start_port = int(input("Enter the starting port number: ")) end_port = int(input("Enter the ending port number: ")) except ValueError: print("Error: Please enter valid numbers for the ports.") sys.exit()

scan_ports(target, start_port, end_port)

Code Explanation:

Imports:

socket: Provides low-level network interactions to create connections.

sys: Allows the script to exit if a problem arises.

scan_ports Function:

Target Resolution: Converts the target hostname into an IP address.

Port Scanning Loop: Iterates through the given port range; for each port:

Creates a new socket.

Uses socket.connect_ex() to attempt a connection (which returns 0 if successful).

Prints the port as open if the connection is established.

Closes the socket after each attempt.

Main Block:

Prompts the user for a target and the range of ports to scan.

Calls the scan_ports() function with the provided parameters.

4. Run Your Script Navigate to the Script’s Directory:

In my case I will be opening visual code studio Follow On-Screen Prompts:

You’ll be asked to enter the target hostname/IP address and the port range (for example, ports 1 to 100).

The script will then display which ports within that range are open. After running the script and waiting approx 5 mins I did get results. Keep in mind the wider the range there will be a wait time.