open-ports-and-programs.py

open-ports-and-programs.py is a cross-platform Python script that enumerates local network connections (both listening and non-listening), listing the corresponding ports, process names, PIDs, and optional DNS lookups. It acts as a flexible alternative to classic tools like netstat or lsof, incorporating regex-based filtering, continuous monitoring, and various sorting options.

Features

1. Port & Process Mapping

   • Automatically discovers open ports and correlates them to processes/PIDs using psutil.

2. Sorting Options

   • Sort by PID, Port, or Program name for easy navigation of large connection lists.

3. Regex Filtering

   • Include or exclude connections by process name or ports using regex (e.g., -r "(chrome|firefox|opera)").

4. Continuous Monitoring

   • With -c/--continuous [INTERVAL], repeatedly update the list of open ports for real-time tracking.

5. DNS Resolution

   • Use -d/--dns to resolve remote IP addresses to hostnames, providing more recognizable output.

6. Bare Output for Scripting

   • -b/--bare yields minimal formatting, perfect for piping or further script consumption.

Installation

1. Clone the Repository

   git clone https://github.com/djdarcy/dazzle.git
   cd dazzle
   

2. Install Dependencies

pip install psutil pytz

• psutil: to inspect processes and network connections.
• pytz: (and the standard library datetime) handle timezones for the script’s output.

3. Run the Script

python open-ports-and-programs.py [options]

Usage Examples

1. Basic Invocation

List all listening and non-listening connections, sorted by Program (default):

python open-ports-and-programs.py

2. Sort by Port

python open-ports-and-programs.py --port

Equivalent to -p, sorts results by numeric port values.

3. Show Only Listening Connections

python open-ports-and-programs.py --listening

Limits results to just connections in the LISTEN state.

4. Continuous Monitoring

# Refresh every 5 seconds, sorting by Port
python open-ports-and-programs.py -p --continuous 5

5. Filter by Regex

# Only show connections for Chrome, Firefox, or Opera; sort by PID
python open-ports-and-programs.py --pid --regex "(chrome|firefox|opera)"

6. Resolve DNS

python open-ports-and-programs.py --dns

Converts remote IPs to hostnames.

Command-Line Options / Reference

Argument	Description
-s {PID,Port,Program}, --sort {PID,Port,Program}	Full: Sort by PID, Port, or Program (default: Program).
-i, --pid	Quick: Sort output by PID (Process ID).
-p, --port	Quick: Sort output by Port.
-b, --bare	Bare output format, suitable for use in scripts.
-l, --listening	Show only connections in the LISTEN state.
-d, --dns	Resolve remote IP addresses to domain names for better readability.
-r REGEX, --regex REGEX	Filter connections using a regex pattern applied to process names or ports.
-c [CONTINUOUS], --continuous [CONTINUOUS]	Continuously monitor network connections at the specified interval in seconds (default: 10s).
-h, --help	Show the help message and exit.

Known Limitations

1. DNS Resolution Overhead
   • Repeated DNS lookups in --continuous mode can slow performance. Consider caching or skipping DNS for large lists.
2. PID Caching
   • PIDs are retrieved repeatedly for each connection, which adds overhead. A simple memoization or dictionary cache could make frequent scans more efficient.
3. Platform Permissions
   • Some OSes require elevated privileges or additional permissions for listing certain connections or processes.

Contributing

Contributions are welcome. Feel free to:

1. Fork the repository.
2. Make changes on a new branch (e.g., feature/add-protocol-filter).
3. Submit a pull request with a clear description of your modifications.

Like the project?

License

open-ports-and-programs.py, Copyright (C) 2025 Dustin Darcy

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.