So your unlimited download time starts at 2 AM and you are feeling too sleepy to wake up at that time. You have a PC running Linux, and like all lazy human beings, you feel that its task of a computer to do things automated by himself. Thankfully there is a way, so that you can suspend your PC and turn it on at a specified time.
rtcwake is a utility with the help of which you can turn off/suspend your PC now and tell it automatically to turn on itself/wake up at a specified time. This is especially useful if you have to do some task later and you would like to save power till then. The basic usage of the command is:
sudo rtcwake -m [type of suspend] -s [number of seconds]
eg, if you would like to hibernate and wake the computer after 60 seconds automatically.
sudo rtcwake -m disk -s 60
The description of type of suspend is given below:
The -m switch accepts the following types of suspend:
- standby – little power savings but quick restorations
- mem – Suspend to RAM. Low power used
- disk – Suspend to disk. No power used as the PC is in switched off state
- off – Turn the computer off completely. This doesn't work (yet).
- no – set the wake up time. In the above options, the computer sleeps immediately, but in this one, you have to manually let it sleep
Apart for number of seconds using -s, you can also specify
- -t To wake your PC at a time specified by number of seconds since UTC epoch.
- -l wake up at specified local time
- -u wake up at specified UTC time
Try yourselves and let us know your experiences.