portwho

Small CLI utility to find which process is using a port and optionally stop it.

What it does

portwho helps you:

• inspect a TCP or UDP port
• see which process is bound to that port
• view basic process information
• optionally terminate that process
• optionally force kill it if graceful termination does not work

This is useful when a local server fails to start because a port is already occupied.

Features

• supports TCP and UDP
• shows PID, process name, executable path, command line, and status
• groups listeners by process
• can terminate processes on the target port
• supports graceful stop with optional force kill fallback
• simple terminal output

Installation

Clone the repository and install it in a virtual environment.

pipx install portwho

or with uv

uv tool install portwho

Requirements

• Python 3.10+
• psutil

Usage

Basic form:

portwho <port>

Examples:

portwho 8000
portwho 8000 --protocol tcp
portwho 53 --protocol udp
portwho 8000 --kill
portwho 8000 --force

Command line arguments

port

Target port number.

Example:

portwho 8000

--protocol {tcp,udp}

Choose which protocol to inspect.

Default:

tcp

Examples:

portwho 8000 --protocol tcp
portwho 53 --protocol udp

--kill

Try to stop processes using the port.

Example:

portwho 8000 --kill

--force

If normal termination times out, force kill the process.

Example:

portwho 8000 --force

Notes

• process termination may fail due to insufficient permissions
• some system or protected processes may not expose full metadata

License

MIT License.