battery-level
This utility reports on the remaining battery percentage and charging status of macOS-based computers. It is intended to be incorprated into shell prompts, terminal-based editor status-lines, scripts, etc.
Usage
Macs can have multiple power sources (though it's rare). Use the --list flag
to tell you how many sources you have, and then --index:<num> to select the
source you want. Note that it is a zero-based array, so if you have one source,
then use --index:0. The default output is the percentage of battery remaining.
$ battery-level --list
1
$ battery-level --index:0
48
There is also a handy --default flag to automatically select the first source.
$ battery-level --default
48
You can pass the flag --charging, which will return 1 if the battery is
currently charging, and 0 if it is not. Cases where it will return 0 include
when the computer is not plugged in, as well as when it is plugged in but the
battery is full.
Both of these result in the same output:
$ battery-level --index:0 --charging
0
$ battery-level --default --charging
0
Example Shell Integration
You can put the following in your ~/.bashrc
prompt_battery() {
charge=$(battery-level --default --charging)
if [[ $charge -eq 1 ]]; then
echo '⚡️'
fi
}
export PS1="\$(prompt_battery) \d \@ \w $ "
And, if the battery is charging, your prompt will look like
⚡️ Mon Feb 27 10:18 AM ~/Development/battery-level $