battery

A Bash program to print your Linux machine’s battery level.

1. Download
2. Use
3. Example output
4. Exit codes
5. How it works
6. Why I made this
7. License

Download

curl -O https://cszach.github.io/battery/battery
chmod +x battery
mv battery ~/.local/bin  # Optional

Use

Get help

battery --help

Print the battery level

battery

Print the battery level of BAT1

battery BAT1

List batteries and power supplies

battery --list

Print the battery level and colorize

battery --color=always

Print the battery level of BAT1 and colorize only if it is charging

battery --color=charging BAT1

Example output

75%

Exit codes

echo $?

• 0: Successful.
• 1: Invalid option.
• 2: Battery could not be found.
• 3: Battery’s level could not be accessed.

How it works

• Power supplies are found in /sys/class/power_supply.
• The battery level is found in /sys/class/power_supply/BATTERY/capacity where BATTERY is a power source detected by your Linux system.
• The charging state is found in /sys/class/power_supply/BATTERY/status. The content of this file is either Charging, Discharging, Full, or Unknown.

Why I made this

I didn’t want to use a graphical desktop on my Parabola GNU/Linux-libre laptop so I needed a way to know the battery level in the command line. I wanted the output to be colorized, too (e.g. green for good battery level, red for weak battery), so it was more than just a one-liner. Ultimately, I figured out I could share this little Bash script with the Internet, so I decided to support user-given power source and push this onto GitHub.

You can easily integrate this program with your PS1 command prompt, like this:

# ~/.bashrc

PS1="$(battery) $"

License

This work is licensed under the Creative Commons Zero v1.0 Universal and is therefore a dedication to the public domain. This means you can copy, modify, and redistribute the program without asking for permission.