Display battery status on OSX, including progress bar

osx-battery-status.sh

#!/bin/bash
# Usage: osx-battery-status.sh [width of progress bar]
# If specified, will use $width characters to display a progress bar, padding with spaces
# Uses half block when needed

ioreg="`ioreg  -c AppleSmartBattery`"
current=`echo "$ioreg" | grep CurrentCapacity | grep -oE "[0-9]+"`
max=`echo "$ioreg" | grep MaxCapacity | grep -oE "[0-9]+"`
battery=$(( $current * 100 / $max ))

if [[ -n "$1" ]]; then
    width="$1"
    if [[ "$width" -gt 0 ]]; then
        val=$(( $battery * 2 * $width / 100 ))
        for (( i = 1; i <= $width; i++ )); do
            if [[ $val -ge $(( $i * 2 )) ]]; then
                echo -ne '\xE2\x96\x88'
            elif [[ $val -ge $(( $i * 2 - 1)) ]]; then
                echo -ne '\xE2\x96\x8C'
            else
                echo -n ' '
            fi
        done
        echo -ne '\xe2\x8e\xb8'
        # echo -ne '\xe2\x94\x82'
    fi
fi

# Pad with a space
printf '%3d%%' $battery