shell-scripts: Use [[ instead of [ where possible

Replace all occurrences of [ with [[ in bash and zsh scripts and
configs.
Performance wise it makes sense to use the builtin instead of calling an
external command also when from a functionality stand point `test` would
suffice.

.config/polybar/launch.sh

@@ -24,7 +24,7 @@ if ! pgrep -ax polybar >/dev/null 2>&1; then
 	primary="$(xrandr -q | grep primary | cut -d' ' -f1)"
 	for m in $(polybar --list-monitors | cut -d':' -f1); do
 		export TRAY_POS=none
-		[ "$m" != "$primary" ] || export TRAY_POS=right
+		[[ "$m" != "$primary" ]] || export TRAY_POS=right
 		export MONITOR="$m"
 		polybar --reload -c "$BASE_DIR/config" main &
 	done

.config/polybar/scripts/battery.sh

@@ -17,13 +17,13 @@ declare -a ramp
 ramp=(          )
 
 # display in red when under $low and no charger is connected
-[ "$bat" -gt "$low" ] || [ "$ac" -eq 1 ] || color="$red"
+[[ "$bat" -gt "$low" || "$ac" -eq 1 ]] || color="$red"
 # display in green when over $full and a charger is connected
-[ "$bat" -lt "$full" ] || [ "$ac" -eq 0 ] || color="$green"
+[[ "$bat" -lt "$full" || "$ac" -eq 0 ]] || color="$green"
 
 let "icon_index = $bat / (${#ramp[@]} - 1)"
-[ $icon_index -lt ${#ramp[@]} ] || icond_index=10
+[[ $icon_index -lt ${#ramp[@]} ]] || icond_index=10
 icon="${ramp[$icon_index]}"
-[ "$ac" -eq 0 ] || charge=""
+[[ "$ac" -eq 0 ]] || charge=""
 
 echo "${color}${icon}${charge} ${bat}%"

.config/polybar/scripts/bluetooth.sh

@@ -3,7 +3,7 @@
 
 bluetooth_print() {
     bluetoothctl | while read -r; do
-        if [ "$(systemctl is-active "bluetooth.service")" = "active" ]; then
+        if [[ "$(systemctl is-active "bluetooth.service")" = "active" ]]; then
 
             devices_paired=$(echo paired-devices | bluetoothctl | sed -n '/paired-devices/,$p' | grep Device | cut -d ' ' -f 2)
             counter=0
@@ -14,7 +14,7 @@ bluetooth_print() {
                 if echo "$device_info" | grep -q "Connected: yes"; then
                     device_alias=$(echo "$device_info" | grep "Alias" | cut -d ' ' -f 2-)
 
-                    if [ $counter -gt 0 ]; then
+                    if [[ $counter -gt 0 ]]; then
                         printf ", %s" "$device_alias"
                     else
                         printf ": %s" "$device_alias"