*.sh: Fix some shellcheck issues

.config/polybar/launch.sh

@@ -15,17 +15,17 @@ module_flags=(
 	[vpn_click_left]="$BASE_DIR/scripts/pub_ipv4.sh &"
 )
 for module in "${!module_flags[@]}"; do
-	export POLYBAR_${module^^}="${module_flags[$module]}"
+	export POLYBAR_"${module^^}=${module_flags[$module]}"
 done
 
 # if there is no running instance
 if ! pgrep -ax polybar >/dev/null 2>&1; then
 	# launch Polybar on every monitor
 	# https://github.com/polybar/polybar/issues/763
-	while read m; do
+	while read -r m; do
 		export MONITOR="${m%%:*}"
 		polybar --reload -c "$BASE_DIR/config" main &
-	done <<<$(polybar --list-monitors)
+	done <<<"$(polybar --list-monitors)"
 
 	echo "Polybar launched..."
 else

.config/polybar/scripts/battery.sh

@@ -9,7 +9,6 @@ low=20
 
 red='%{F#f00}'
 green='%{F#0f0}'
-end='%{F-}'
 
 bat="$(cat /sys/class/power_supply/BAT0/capacity 2>/dev/null)" || exit
 ac="$(cat /sys/class/power_supply/AC/online 2>/dev/null)"
@@ -21,8 +20,8 @@ ramp=(          )
 # display in green when over $full and a charger is connected
 [[ "$bat" -lt "$full" || "$ac" -eq 0 ]] || color="$green"
 
-let "icon_index = $bat / (${#ramp[@]} - 1)"
-[[ $icon_index -lt ${#ramp[@]} ]] || icond_index=10
+icon_index="$((bat / (${#ramp[@]} - 1)))"
+[[ $icon_index -lt ${#ramp[@]} ]] || icon_index=10
 icon="${ramp[$icon_index]}"
 [[ "$ac" -eq 0 ]] || charge=""
 

.config/polybar/scripts/pub_ipv4.sh

@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
 
-echo $(curl -s https://ipinfo.io/ip)
+curl -s https://ipinfo.io/ip