Check Battery Existence before Calling and Printing Content

This ensures that the script does not return errors when operating in
environments without batteries, as if there are no battery-related files
in the target directory, the script now stops from accessing the files
to begin with.

Author: thekpaul

scripts/battery_percentage.sh

@@ -7,10 +7,8 @@ source "$CURRENT_DIR/helpers.sh"
 print_battery_percentage() {
 	# percentage displayed in the 2nd field of the 2nd row
 	if is_wsl; then
-		local battery=$(find /sys/class/power_supply/*/capacity | tail -n1)
-		if [ -n "$battery" ]; then
-			echo $(cat "$battery")%
-			return
+		if [ -e /sys/class/power_supply/*/capacity ]; then
+			echo $(cat $(find /sys/class/power_supply/*/capacity | tail -n1))%
 		fi
 	elif command_exists "pmset"; then
 		pmset -g batt | grep -o "[0-9]\{1,3\}%"