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

[bash]
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
}
[/bash]

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:

[bash]
battery_percentage=”$(get_battery)%%”

directory_info=”${_prompt_steeef_colors[5]}%~%f”

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} ${vcs}
“”$ “

RPROMPT=””
[/bash]

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: