add waybar-void-update-checker

templates/.config/waybar/config.jsonc.j2

@@ -10,6 +10,7 @@
     "modules-center": [
     ],
     "modules-right": [
+        "custom/void-updates",
 
 {% for iface in host.wireless + host.ethernet %}
         "network#{{ iface }}",
@@ -37,6 +38,14 @@
     "niri/workspaces": {
         "format": "\uf111"
     },
+
+    "custom/void-updates": {
+        "exec": "waybar-void-update-checker",
+        "hide-empty-text": true,
+        "return-type": "json",
+        // every 7 hours
+        "interval": 25200,
+    },
     
 {% for iface in host.wireless %}
     "network#{{ iface }}": {

templates/bin/waybar-void-update-checker

@@ -0,0 +1,12 @@
+#!/bin/sh
+
+set -e
+
+info="$(xbps-install -Mun)"
+
+PKG_COUNT="$(echo "$info" | wc -l)"
+[ $PKG_COUNT -eq 0 ] && exit
+
+DL_SIZE="$(echo "$info" | awk '{s+=$6}END{print s}' | numfmt --to=iec-i)B"
+
+echo '{"text": "\uf468 '"$PKG_COUNT"'", "tooltip": "'"$PKG_COUNT"' packages have updates; '"$DL_SIZE"' download"}'