A Cross-OS Port Finder in Rust — One CLI, Three Completely Different Data Formats

A Cross-OS Port Finder in Rust — One CLI, Three Completely Different Data Formats A tiny Rust CLI that answers "who is holding port 3000?" on macOS, Linux and Windows with the same flags and the same output shape — and optionally kills the offender. 488 KB binary, 42 tests, zero external crates beyond clap + serde . npm run dev dies with EADDRINUSE: address already in use :::3000 and once again there's a zombie Node sitting on the port. On macOS the incantation is lsof -nP -iTCP:3000 -sTCP:LISTE