Cross-platform CLI to inspect and kill processes by port

Portslayer

Cross-platform CLI to inspect and kill processes by port on Windows, macOS, and Linux.

Why Portslayer

• Works across all major desktop/server operating systems.
• Interactive by default when run in a terminal.
• Script-friendly with flags and JSON output.
• Clear kill summaries and actionable failure messages.

Install

npm install -g portslayer-cli

Quick Usage

portslayer list
portslayer check 3000
portslayer kill 3000

Commands

portslayer list

Lists listening TCP ports and process ownership.

Flags:

• --json machine-readable output
• --no-color disable colors
• --verbose include extra details

portslayer check <port>

Checks whether a specific port is in use.

Exit code behavior:

• 0 port is free
• 1 port is occupied
• 2 invalid user input (for example invalid port)

portslayer kill [port]

Kills process(es) bound to the target port.

If port is omitted in interactive terminals, portslayer prompts for it.

Flags:

• --port <number> provide port as named option
• --all kill all PIDs listening on the port
• --force force termination (taskkill /F, kill -9)
• --dry-run show what would be killed
• --yes skip confirmation prompt
• --json machine-readable output

Examples

# Interactive kill flow
portslayer kill

# Kill all processes on port 5173 without confirmation
portslayer kill 5173 --all --yes

# CI-friendly JSON mode
portslayer check 8080 --json

# Inspect before kill
portslayer kill 3000 --dry-run

Local Development

npm install
npm run lint
npm run typecheck
npm test
npm run build

Run compiled CLI:

node dist/cli.js list

Publish to npm

1. Login to npm:

   npm login

2. Publish:

   npm publish --access public

Optional release automation with np:

npx np

Contributing

Please read CONTRIBUTING.md before opening pull requests.

Security

Please read SECURITY.md for vulnerability reporting.

Troubleshooting

• Linux/macOS: if process metadata is missing, run with higher permissions.
• Linux: if lsof is unavailable, install it or ensure ss is present.
• Windows: if kill fails, retry with elevated terminal and --force.