The latest articles on DEV Community by Adeyomi Lawal (@adeyomi_lawal_8c61225e087). https://dev.to/adeyomi_lawal_8c61225e087 https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F3583471%2F1160ad7d-880f-4e48-8b32-330e8f43563d.png https://dev.to/adeyomi_lawal_8c61225e087 en Adeyomi Lawal Wed, 29 Oct 2025 13:38:20 +0000 https://dev.to/adeyomi_lawal_8c61225e087/building-a-cross-platform-cli-tool-with-typescript-3f69 https://dev.to/adeyomi_lawal_8c61225e087/building-a-cross-platform-cli-tool-with-typescript-3f69 <p><strong>The Problem</strong></p> <p>Every developer has seen this error:</p> <p><code>\</code><code><br> Error: Port 3000 is already in use<br> \</code><code>\</code></p> <p>And every developer has done this:</p> <ol> <li>Open Google</li> <li>Search "how to kill port process [your OS]"</li> <li>Copy-paste: <code>lsof -ti :3000 | xargs kill -9</code> (macOS)</li> <li>Hope it works</li> <li>Repeat tomorrow</li> </ol> <p>After doing this 100+ times, I decided to build a solution.</p> <p><strong>Introducing zkill</strong></p> <p><a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Fkz0dsr5wy6gpfged5mor.png" class="article-body-image-wrapper"><img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Fkz0dsr5wy6gpfged5mor.png" alt=" " width="800" height="387"></a></p> <p><code>zkill</code> is a cross-platform CLI tool that kills zombie processes in one command:</p> <p><code>\</code><code>bash<br> zkill 3000<br> \</code><code>\</code></p> <p>That's it. Works on Mac, Linux, and Windows.</p> <h2> Features </h2> <ul> <li>🎯 <strong>Smart detection</strong> - Shows what process is using the port</li> <li>🔒 <strong>Safe mode</strong> - Asks for confirmation before killing</li> <li>🧠 <strong>Project-aware</strong> - Remembers which ports belong to which projects</li> <li>⚡ <strong>Fast</strong> - Less than 100ms to detect processes</li> <li>🎨 <strong>Beautiful CLI</strong> - Color-coded output with spinners</li> </ul> <h2> Installation </h2> <p><code>\</code><code>bash<br> npm install -g zombie-port-killer<br> \</code><code>\</code></p> <h2> Quick Start </h2> <p><code>\</code>`bash</p> <h2> Kill process on port 3000 </h2> <p>zkill 3000</p> <h2> Kill without confirmation </h2> <p>zkill 3000 --force</p> <h2> List all active ports </h2> <p>zkill scan</p> <h2> Show system info </h2> <p>zkill info<br> `<code>\</code></p> <h1> Technical Deep Dive </h1> <h2> Architecture </h2> <p>I built zkill using a cross-platform adapter pattern. Each OS has its own adapter:</p> <ul> <li> <strong>macOS</strong>: Uses <code>lsof</code> and <code>ps</code> </li> <li> <strong>Linux</strong>: Uses <code>ss</code> (or <code>netstat</code> fallback) and <code>ps</code> </li> <li> <strong>Windows</strong>: Uses <code>netstat</code> and <code>tasklist</code>/<code>taskkill</code> </li> </ul> <p>[Code snippet of adapter pattern]</p> <h2> TypeScript Setup </h2> <p>Built entirely in TypeScript for type safety and better DX:</p> <p><code>\</code><code>json<br> {<br> "compilerOptions": {<br> "target": "ES2020",<br> "module": "commonjs",<br> "strict": true,<br> // ...<br> }<br> }<br> \</code><code>\</code></p> <h2> Testing </h2> <p>114 tests covering all major functionality:</p> <ul> <li>Unit tests for services</li> <li>Integration tests for commands</li> <li>Cross-platform compatibility tests</li> </ul> <p><code>\</code><code>bash<br> npm test<br> \</code><code>\</code></p> <h1> What I Learned </h1> <h2> 1. Cross-Platform is Hard </h2> <p>Different operating systems use completely different commands for process management. Windows was particularly challenging.</p> <h2> 2. UX Matters in CLI Tools </h2> <p>Even in a terminal, UX matters:</p> <ul> <li>Color-coded output</li> <li>Loading spinners</li> <li>Clear error messages</li> <li>Helpful prompts</li> </ul> <h2> 3. Testing Saves Time </h2> <p>Comprehensive tests caught platform-specific bugs early and gave me confidence to ship.</p> <h2> 4. Documentation is Critical </h2> <p>A good README is the difference between 0 users and 1000 users.</p> <h1> Roadmap </h1> <p>Coming in v1.1:</p> <ul> <li>Kill multiple ports: <code>zkill 3000 8000 5432</code> </li> <li>Kill by process name: <code>zkill --name node</code> </li> <li>Port range support: <code>zkill --range 3000-3010</code> </li> </ul> <h1> Try it Out! </h1> <p><code>\</code><code>bash<br> npm install -g zombie-port-killer<br> zkill --help<br> \</code><code>\</code></p> <p><strong>Links:</strong></p> <ul> <li>📦 <a href="https://www.npmjs.com/package/zombie-port-killer" rel="noopener noreferrer">npm package</a> </li> <li>⭐ <a href="https://github.com/adeyomilawal/zombie-port-killer" rel="noopener noreferrer">GitHub</a> </li> <li>🐛 <a href="https://github.com/adeyomilawal/zombie-port-killer/issues" rel="noopener noreferrer">Issues/Feedback</a> </li> <li><a href="https://zkill.dev" rel="noopener noreferrer">Website</a></li> </ul> <p>What do you think? What features would you like to see next?</p> <p><em>If you found this useful, please star the repo and share it with other developers!</em><br> <code>\</code>`</p> typescript javascript cli opensource