Getting battery percentage in zsh

I’m on osx maverick still at home on my laptop and I spent part of today dicking around customizing my zsh shell. I wanted to be able to show my battery percentage in the shell and it’s really pretty easy.

First, the main shell function

function get_battery()
    current_battery=`system_profiler SPPowerDataType | grep -i "charge remaining" | awk '{print $4}'`

    max_battery=`system_profiler SPPowerDataType | grep -i "full charge capacity" | awk '{print $5}'`

    percent=`bc <<< "scale=4; ${current_battery}/${max_battery} * 100"`

    printf '%.0f' $percent 

This queries from the profiler the charge current and remaining, uses bc to get a floating point division, and then just shows the integer value of that (we could round it too but I was lazy).

Now, we just need to tie it into the prompt. I’m using the steef prompt by default and just tweaked it a bit:



datetime="%F{yellow}[%D{%a %I:%M:%S %p}]%f" # yellow [Day hh:mm:ss am/pm] followed by reset color %f

PROMPT="${battery_percentage} ${datetime} ${directory_info} ${vcs} 
""$ "


The two percent symbols just escapes the percent symbol.

Make sure the battery_percentage function is defined before you load your prompt in your .zshrc file.

Now here’s what I got:

Screen Shot 2015-03-29 at 6.13.50 PM

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