log-tee

Run commands and log their output to a file while displaying in terminal (like Unix tee command).

Installation

You don't need to install it! Just use npx:

npx log-tee <logfile> <command> [args...]

Or install globally:

npm install -g log-tee

Usage

With npx (recommended)

npx log-tee output.log npm run dev

npx log-tee build.log npm run build

npx log-tee vite.log npm run dev-full

After global install

log-tee output.log npm run dev

Features

• Captures both stdout and stderr
• Displays output in real-time in the terminal
• Logs everything to a file simultaneously
• Adds timestamps to log entries
• Preserves exit codes
• Handles SIGINT/SIGTERM gracefully
• Preserves ANSI colors in terminal
• Works with any command
• Cross-platform: Windows, Mac, Linux

Examples

Run Vite dev server and log output:

npx log-tee vite.log npm run dev

Run tests and log results:

npx log-tee test-results.log npm test

Run any command:

npx log-tee output.log node script.js

Chain commands:

npx log-tee build.log sh -c "npm run build && npm run deploy"

Why use log-tee?

• Debug issues locally: Keep logs of your dev or build processes
• Development: Monitor long-running processes while keeping a record
• No platform dependency: Works on Windows, Mac, and Linux

How it's different from shell redirection

Instead of:

npm run dev > output.log 2>&1  # No terminal output
npm run dev 2>&1 | tee output.log  # Requires tee (not on all systems)

Just use:

npx log-tee output.log npm run dev  # Cross-platform, always works

License

MIT