#!/bin/bash
# 设备重启了 —— 查是掉电、还是崩溃、还是被谁重启的
set -u

echo "════════ 1. 这次开机的起点 ════════"
uptime | sed 's/^/  /'
echo "  当前时间: $(date '+%m-%d %H:%M:%S')"
echo "  开机时刻: $(uptime -s 2>/dev/null || echo '?')"

echo
echo "════════ 2. 上一次关机是干净的还是掉电 ════════"
echo "  --- last reboot ---"
last -x reboot 2>/dev/null | head -6 | sed 's/^/  /'
echo "  --- last shutdown ---"
last -x shutdown 2>/dev/null | head -4 | sed 's/^/  /'

echo
echo "════════ 3. 本次启动的日志开头（看有没有异常）════════"
journalctl -b --no-pager 2>/dev/null | head -25 | sed 's/^/  /'

echo
echo "════════ 4. 有没有内核崩溃 / 掉电迹象 ════════"
echo "  --- 上次启动末尾（也就是重启前最后的日志）---"
journalctl -b -1 --no-pager 2>/dev/null | tail -25 | sed 's/^/  /'
echo
echo "  （如果上面是空的，说明上次的日志没落盘 —— 典型的直接掉电）"

echo
echo "════════ 5. dmesg 里的告警 ════════"
dmesg 2>/dev/null | grep -iE 'error|warn|fail|thermal|voltage|under' | tail -12 | sed 's/^/  /'
echo "  （没输出=没有明显告警）"

echo
echo "════════ 6. 温度 / 电压（如果是过热或欠压会重启）════════"
for f in /sys/class/thermal/thermal_zone*/temp; do
    [ -f "$f" ] && echo "  $f: $(($(cat $f) / 1000))°C"
done
command -v vcgencmd >/dev/null 2>&1 && vcgencmd measure_temp 2>/dev/null | sed 's/^/  /'
cat /sys/class/power_supply/*/voltage_now 2>/dev/null | while read v; do
    echo "  电压: $((v / 1000)) mV"
done

echo
echo "════════ 7. 内存压力（OOM 会把系统搞挂）════════"
free -m | sed 's/^/  /'
echo "  本次启动有没有 OOM:"
journalctl -b --no-pager 2>/dev/null | grep -ic 'out of memory\|oom-kill' | sed 's/^/    /'

echo
echo "════════ 8. 是不是被关机命令重启的 ════════"
journalctl -b --no-pager 2>/dev/null | grep -iE 'shutdown|reboot|poweroff|systemd-logind' | head -8 | sed 's/^/  /'

echo
echo "════════ 9. 日志持久化了吗（掉电的话日志会丢）════════"
echo "  /var/log/journal 存在: $(if [ -d /var/log/journal ]; then echo 是; else echo '否（日志只在内存里，重启就没）'; fi)"
echo "  当前 journal 占用: $(journalctl --disk-usage 2>/dev/null | sed 's/.*take up //' || echo '?')"