the job you want to delete, type dd to delete that line. If you want to delete all
your jobs, you can use crontab -r to delete your crontab file.
Read the man page for more about cron.
Using rtcwake to Wake Your Computer from
Sleep Automatically
Some of us keep our computers running 24/7. Perhaps you don’t want to do
so, and you need to have your system up and running at a certain time every
day, but you can’t guarantee that you will be able to be present to turn it on. It
is possible to use rtcwake to place the computer in sleep or suspend mode
instead of turning it off and then wake up the computer later. To do this, you
must have sudo permissions. Here is an example:
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matthew@seymour:~$ sudo rtcwake -m mem -s -3600
This command tells the computer to suspend to RAM, or sleep, which means
to save the current state of the computer in memory and shut down everything
else and then to wake the computer after 3600 seconds, which is one hour.
Here is the basic syntax of the command:
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sudo rtcwake -m [type of suspend] -s [number of seconds]
There are five types of suspend available to use with -m:
disk—(hibernate) The current state of the computer is written to disk,
and the computer is powered off.
mem—(sleep) The current state of the computer is written to RAM, and
the computer is put into a low-power state, using just enough power to
keep the memory preserved.
no—The computer is not suspended immediately. Only the wakeup time
is set. This allows you to continue working; you have to remember to put
the computer to sleep manually.
off—The computer is turned off completely. Wake will not work with
this setting for everyone and is not officially supported, but it does work
with some computers. It is included here for those who like to live
dangerously.
standby—The computer is put into standby mode, which saves some