is_port_open

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Filename: is_port_open.py
# Version: 1.00
# Author: Jeoi Reqi

"""
This script enables users to check for open ports and listen on a specific port if desired.

Functions:
    - get_ports_in_use(): Retrieves a dictionary of ports currently in use along with associated process information.
    - list_ports_in_use(ports_in_use): Displays the list of ports in use along with their associated processes.
    - prompt_user_to_save_data(ports_in_use): Prompts the user whether to save the ports in use data to a file named 'inuse.txt'.
    - prompt_user_for_port(): Prompts the user to enter the port number they want to listen on.
    - listen_on_port(selected_port): Listens on the selected port for incoming connections and displays received data.
    - save_selected_port_data(selected_port, ports_in_use): Saves the data associated with the selected port to a file.

Features:
    - Retrieves a list of ports currently in use on the local system along with associated process information.
    - Displays the list of ports in use, providing process details for each port.
    - Allows the user to save the ports in use data to a text file for further analysis.
    - Prompts the user to select a port to listen on, then listens on that port for incoming connections.
    - Saves data related to the selected port to a text file for reference.

Requirements:
    - Python 3.x
    - psutil library (install via pip: pip install psutil)

Usage:
    1. Ensure Python 3.x is installed on your system.
    2. Install the psutil library by running: pip install psutil
    3. Save the script as 'is_port_open.py'.
    4. Execute the script using the command: python is_port_open.py
    5. Follow the prompts to view ports in use, select a port to listen on, and save data if desired.

Notes:
    - This script retrieves information about ports in use and listens for incoming connections on the local system.
    - It may require elevated privileges to gather process information depending on the system's security settings.
    - The 'inuse.txt' file will be created in the same directory as the script if the user chooses to save data.
    - Ensure to review the contents of the saved data files, as they may contain sensitive information.
"""

import psutil
import socket

# Function to get the list of ports in use
def get_ports_in_use():
    """
    Retrieves a dictionary of ports currently in use along with associated process information.

    Returns:
        dict: A dictionary containing port numbers as keys and sets of process information tuples as values.
    """
    ports_in_use = {}
    for conn in psutil.net_connections():
        if conn.laddr.port not in ports_in_use:
            ports_in_use[conn.laddr.port] = set()
        if conn.pid is None:
            process = {'pid': -1, 'name': 'UNKNOWN', 'program': 'UNKNOWN'}
        else:
            try:
                cmdline = psutil.Process(conn.pid).cmdline()
                program = ' '.join(cmdline) if cmdline else 'UNKNOWN'
                process = {'pid': conn.pid, 'name': psutil.Process(conn.pid).name(), 'program': program}
            except (psutil.NoSuchProcess, psutil.AccessDenied, psutil.ZombieProcess):
                process = {'pid': conn.pid, 'name': 'UNKNOWN', 'program': 'UNKNOWN'}
        ports_in_use[conn.laddr.port].add((process['pid'], process['name'], process['program']))
    return ports_in_use

# Function to list ports in use
def list_ports_in_use(ports_in_use):
    """
    Displays the list of ports in use along with their associated processes.

    Args:
        ports_in_use (dict): A dictionary containing port numbers as keys and sets of process information tuples as values.
    """
    for port, processes in sorted(ports_in_use.items()):
        print("\n" + "-" * 40)
        for process in processes:
            pid, name, program = process
            if name == 'svchost.exe' and program == 'UNKNOWN':
                print(f"\n{name}")
            else:
                print(f"\n{name}")
                print(f"Port: {port}, PID: {pid}    {program}")

# Function to prompt user to save data
def prompt_user_to_save_data(ports_in_use):
    """
    Prompts the user whether to save the ports in use data to a file named 'inuse.txt'.

    Args:
        ports_in_use (dict): A dictionary containing port numbers as keys and sets of process information tuples as values.
    """
    while True:
        save_data = input("\nDo you want to save the ports in use data to 'inuse.txt'?\n1: YES\n2: NO\n(Enter your option number): ").strip().lower()
        if save_data == '1':
            with open('inuse.txt', 'w') as file:
                for port, processes in sorted(ports_in_use.items()):
                    for process in processes:
                        pid, name, program = process
                        file.write(f"\n{name}\n")
                        file.write(f"Port: {port}, PID: {pid}    {program}\n")
            print("Ports in use data saved to 'inuse.txt'.")
            break
        elif save_data == '2':
            break
        else:
            print("Invalid input. Please enter '1' for YES or '2' for NO.")

# Function to prompt user for port to listen on
def prompt_user_for_port():
    """
    Prompts the user to enter the port number they want to listen on.

    Returns:
        int: The port number selected by the user.
    """
    while True:
        selected_port = input("Enter the port number you want to listen on: ")
        try:
            selected_port = int(selected_port)
            if selected_port < 1 or selected_port > 65535:
                raise ValueError("Invalid port number.")
            return selected_port
        except ValueError:
            print("Invalid input. Please enter a valid port number.")

# Function to listen on the selected port
def listen_on_port(selected_port):
    """
    Listens on the selected port for incoming connections and displays received data.

    Args:
        selected_port (int): The port number to listen on.
    """
    try:
        with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
            s.bind(('127.0.0.1', selected_port))
            print(f"Listening on port {selected_port}...")
            s.listen(1)
            conn, addr = s.accept()
            with conn:
                print('Connected by', addr)
                while True:
                    data = conn.recv(1024)
                    if not data:
                        break
                    print(f"Received data: {data.decode('utf-8')}")
    except OSError as e:
        print(f"Failed to listen on port {selected_port}: {e}")

# Function to save data for the selected port
def save_selected_port_data(selected_port, ports_in_use):
    """
    Saves the data associated with the selected port to a file.

    Args:
        selected_port (int): The port number selected by the user.
        ports_in_use (dict): A dictionary containing port numbers as keys and sets of process information tuples as values.
    """
    try:
        with open(f'port_{selected_port}_data.txt', 'w') as file:
            file.write(f"Port {selected_port}:\n")
            for process in ports_in_use.get(selected_port, []):
                pid, name, program = process
                file.write(f"PID: {pid}\nProcess: {name}\nProgram: {program}\n\n")
        print(f"Data for port {selected_port} saved to 'port_{selected_port}_data.txt'.")
    except Exception as e:
        print(f"Failed to save data for port {selected_port}: {e}")

# Main function
def main():
    """
    Main function to execute the script.
    """
    # Get ports in use
    ports_in_use = get_ports_in_use()

    # List ports in use
    list_ports_in_use(ports_in_use)

    # Prompt user to save ports in use data
    prompt_user_to_save_data(ports_in_use)

    # Prompt user for port to listen on
    selected_port = prompt_user_for_port()
    print(f"Selected port: {selected_port}")

    # Save data for the selected port
    save_selected_port_data(selected_port, ports_in_use)

    # Listen on the selected port
    listen_on_port(selected_port)

if __name__ == "__main__":
    main()