查看是否安裝rtcwake
whereis rtcwake rtcwake: /usr/sbin/rtcwake /usr/share/man/man8/rtcwake.8.gz
查看rtcwake幫助
rtcwake --help Usage: rtcwake [options] Options: -d, --device <device> select rtc device (rtc0|rtc1|...) -n, --dry-run does everything, but suspend -l, --local RTC uses local timezone -m, --mode <mode> standby|mem|... sleep mode -s, --seconds <seconds> seconds to sleep -t, --time <time_t> time to wake -u, --utc RTC uses UTC -v, --verbose verbose messages -h, --help display this help and exit -V, --version output version information and exit For more details see rtcwake(8).
使用方法
standby
普通待機模式，為默認選項，對應ACPI state S1
mem
待機到內存，即內存之外把其他設備都進入低功耗模式，對應ACPI state S3
disk
待機到硬盤，即休眠，把電腦的當前狀態保存到硬盤，幾乎不消耗外部電源，對應ACPI state S4
off
通過調用系統的關機命令來休眠， 對應ACPI state S5
可以通過以下命令查閱當前系統支持的休眠模式
cat /sys/power/state standby mem disk
執行該命令的時候需要root權限
1. 系統休眠后20seconds喚醒，加-v選項可以看到更多的打印信息
sudo rtcwake -v -s 20 -m mem 或 sudo rtcwake -v -s 20 -m standby
打印信息:
rtcwake -v -s 20 -m mem Using UTC time. delta = 0 tzone = 0 tzname = UTC systime = 1393296617, (UTC) Tue Feb 25 02:50:17 2014 rtctime = 1393296617, (UTC) Tue Feb 25 02:50:17 2014 alarm 0, sys_time 1393296617, rtc_time 1393296617, seconds 20 rtcwake: wakeup from "mem" using /dev/rtc0 at Tue Feb 25 02:50:38 2014 suspend mode: mem; suspending system
2. 系統在指定的時間醒來
rtcwake -v -t `date -d 10:53 +%s` -m mem Using UTC time. delta = 0 tzone = 0 tzname = UTC systime = 1393296754, (UTC) Tue Feb 25 02:52:34 2014 rtctime = 1393296754, (UTC) Tue Feb 25 02:52:34 2014 alarm 1393296780, sys_time 1393296754, rtc_time 1393296754, seconds 0 rtcwake: wakeup from "mem" using /dev/rtc0 at Tue Feb 25 02:53:00 2014 suspend mode: mem; suspending system
rtcwake -v -t `date -d 10:54 +%s` -m standby Using UTC time. delta = 0 tzone = 0 tzname = UTC systime = 1393296794, (UTC) Tue Feb 25 02:53:14 2014 rtctime = 1393296794, (UTC) Tue Feb 25 02:53:14 2014 alarm 1393296840, sys_time 1393296794, rtc_time 1393296794, seconds 0 rtcwake: wakeup from "standby" using /dev/rtc0 at Tue Feb 25 02:54:00 2014 suspend mode: standby; suspending system
如果發現systime 和rtctime時間不一致，需要利用hwclock進行調整。
原文鏈接：https://blog.csdn.net/bulreed/article/details/19907691