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I often (for example on the train) want to put my macbook into a state that will maximise the amount of time I have before the battery runs out - so far example I'll switch off the bluetooth, then switch off the wifi, then alter the brightness - my question is, can I do all of this from the command line? Then I run some nice little script...

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Can you provide a more complete list of the things you want to accomplish? You've got Bluetooth, WiFi, and brightness; is there anything else you want to do? – Nathan Greenstein Feb 12 '12 at 19:33
Those are the only things I do at the moment - if someone suggests something else that can be done from the command line that would help save power (I assume one can probably throttle the processor a little as well) then I'm all ears... – Joe Feb 12 '12 at 19:38
up vote 3 down vote accepted

You can, but you will need some extra utilities:

brightness - you can download the program at and compile it using the command:

gcc -std=c99 -o brightness brightness.c -framework IOKit -framework ApplicationServices

Or you can just download it from my server at

Once you have it, brightness 0.01 will lower the brightness as much as possible

Bluetooth - The command you want is blueutil which you can find here I have a compiled version of that available at I also have another, older version of a program by the same name which you can download from

Whichever program you use, the -h flag will explain how to use it.

Wi-Fi - You can turn AirPort power on or off using:

networksetup -setairportpower <device name> <on off>

where <device name> is probably either en0 or en1

You can find out which it is using

networksetup -listnetworkserviceorder | egrep "Wi-Fi, Device"

For my MacBook Air (which uses en0), the command to turn it off is:

networksetup -setairportpower en0 off

More Settings

Be sure that you have changed the Energy Settings in System Preferences too, but you can also set them using:

sudo pmset -b sleep 10

to tell the computer to sleep after 10 minutes when on battery, and/or:

sudo pmset -b displaysleep 5

to tell the computer display to sleep after 5 minutes, when on battery (the -b flag indicates battery).

pmset -g

will show you your current settings.

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p.s - the newer version of blueutil can be installed from Homebrew using brew install --HEAD blueutil – TJ Luoma Feb 12 '12 at 20:19

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