About

Where it comes from

plugii began as usb-ports, a bash script in its author’s dotfiles: a report of what sat on each socket, at what speed, with the USB-C state and a few health checks at the end. Every time a port misbehaved the script grew another rule, and another fix for one of two laptops. plugii is its rewrite in Rust: the same report, the same rules and the same labels format (feature parity with the script was the baseline), plus what a script can’t do well: a live view, charts over time, and recordings.

Why it exists

Two incidents shaped it, and each became a test fixture for the rule it produced:

• A ThinkPad’s dead USB-C port (September 2026). A monitor on a USB-C port got no picture: the port’s SuperSpeed lanes were down, so there was no USB 3 and no DisplayPort alt mode, and nothing on screen said why. That gave the “hub stuck at USB 2” and “USB-C device but no DisplayPort output” checks, with Lenovo’s EC reset as the fix.
• An XPS 13 throttling on its dock (October 2026). On AC through a dock, the CPU was held down, and UCSI kept a stale view of the dock’s power offers. That gave the BD PROCHOT throttling check and the stale USB-C status check.

The common thread: the kernel knows all of it, spread over sysfs, UCSI and the kernel log, but nothing puts it together by physical socket. plugii does, and keeps doing it while you swap cables.

Design

• One generic core, no hostnames in the code: what differs between machines is discovered (batteries, sensors, peer links), kept in the labels file, or in a vendor module picked by DMI (Lenovo and Dell, for firmware catalogs and advice).
• Readers take a root path, so the whole tool runs against captured sysfs trees in the tests; the report, the TUI screens and the CLI help on this site are those tests’ snapshots.
• std threads and channels, no async runtime: ratatui and crossterm for the TUI, clap for the CLI, udev for events.

License

MIT. The source is at github.com/rdlu/plugii; issues and pull requests are welcome there. Captures of machines plugii gets wrong (plugii capture) are the most useful contribution.

This site is built with Hugo and the Hextra theme (MIT), and set in iA Writer Duo and 0xProto (both SIL OFL 1.1).