vmaltarello / whyd

**Why did my PC stop?**
whyd reads the journal of the previous session and tells you, in one screen, how it ended and
what went wrong before.
Your laptop froze, you held the power button, it came back up. The answer is in the journal,
buried under thousands of harmless lines. whyd finds it:
- **how it ended**: clean power-off or reboot, hard power-off, died asleep, kernel panic
- **what went wrong before**: out-of-memory kills, GPU errors, crashes, failed services,
 hung tasks, overheating, disk errors, each with a short explanation
 (the full list)
- **the last minutes** of the session, with the harmless lines folded away
- **a report** to paste on a forum, with addresses, hostname, user and Wi-Fi names removed
`journalctl -b -1 -p err` shows dozens of harmless errors, and nothing at all when the power
was cut: a hard power-off leaves no error behind. whyd tells the two apart, says how the
session ended, and explains each problem.
whyd only reads the journal: it doesn't go on the network, and on its own it writes nothing but
a small cache of the sessions already read, in `~/.cache/whyd`.
## Install
 [code] 
For ARM, replace `amd64` with `arm64`. Without sudo, the script installs to `~/.local/bin` with
`... | PREFIX=~/.local sh`; to update, run the same line again.
### Requirements
- Linux with systemd: whyd is a single program and needs only `journalctl`.
- A user in the `systemd-journal`, `adm` or `wheel` group (the first user usually is, on
 Ubuntu and Arch); otherwise run whyd with `sudo`.
- A journal kept on disk. If whyd finds only the current session even after a few reboots, the
 journal is kept in memory and lost at every shutdown: `sudo mkdir -p /var/log/journal` and
 reboot, and from then on whyd has the sessions to look at.
## Use
 [code] 
In the interface the arrows do everything: ↑ ↓ move, → and ← switch panel, `Enter` opens a
problem's journal lines. Problems are listed by time, between the moments of the session
(started, asleep, woke up, the end); `T` lists them by importance. `U` keeps only the sessions
that ended badly, `L` shows the last minutes, `R` the report, `?` every key.
## Rules
Problems are recognised by rules written in TOML, not code. Your own go in
`~/.config/whyd/rules/` and can add to, change or turn off the built-in ones. Found a problem
whyd didn't recognise? A rule with a real example line is the best contribution:
docs/RULES.md explains the format step by step, and
CONTRIBUTING.md how to build, test and send changes.
## License
GPL-3.0-or-later