Refresh after pacman transactions and local repo builds

Add a pacman hook that runs update-notify for each logged-in user with the timer active, and a path unit that users can point at their local repo databases to refresh after aur build.

README.md

@@ -42,6 +42,28 @@ systemctl --user enable --now update-notify.timer
 
 The timer runs 5 minutes after boot, then every 6 hours.
 
+A pacman hook also runs update-notify after every pacman transaction, for each logged-in user whose timer is active, so the notification and the status bar file are current right after an upgrade.
+
+### Refresh after building packages
+
+Building into a local repository (`aur build`, `aur sync`) doesn't run pacman, so the hook can't catch it. To run update-notify whenever a repository changes, add the repository files to watch to `update-notify.path`:
+
+```
+systemctl --user edit update-notify.path
+```
+
+```
+[Path]
+PathChanged=/home/aur-local/aur-local.db.tar.gz.sig
+PathChanged=/home/custom-pkgs/custom-pkgs.db.tar.gz.sig
+```
+
+Watch the `.db.tar.gz.sig` file for signed repositories, or `.db.tar.gz` for unsigned ones (`.db` is a symlink). Then enable it:
+
+```
+systemctl --user enable --now update-notify.path
+```
+
 ## Usage
 
 ```
@@ -80,7 +102,7 @@ aur <pkg> <newver>
 kernel <custom-pkg> <stock-ver>
 ```
 
-The file reflects the last run. To keep a bar current after an upgrade, drop entries whose installed version (`pacman -Q`) is no longer older than `newver`, or, for `kernel` lines, whose custom build has caught up with `stock-ver` (ignoring `pkgrel`). This only reads local data, so it's cheap to run often.
+The file reflects the last run, which the pacman hook and `update-notify.path` keep close to current. To keep a bar current in between, drop entries whose installed version (`pacman -Q`) is no longer older than `newver`, or, for `kernel` lines, whose custom build has caught up with `stock-ver` (ignoring `pkgrel`). This only reads local data, so it's cheap to run often.
 
 ## License
 

update-notify-refresh

@@ -0,0 +1,10 @@
+#!/bin/bash
+# Run update-notify for every logged-in user whose timer is active (called by the pacman hook as root)
+systemctl list-units --plain --no-legend --state=running 'user@*.service' |
+while read -r unit _; do
+    uid=${unit#user@}
+    uid=${uid%.service}
+    user=$(id -nu "$uid") || continue
+    systemctl --user -M "$user@" is-active --quiet update-notify.timer || continue
+    systemctl --user -M "$user@" start --no-block update-notify.service
+done

update-notify.hook

@@ -0,0 +1,11 @@
+[Trigger]
+Operation = Install
+Operation = Upgrade
+Operation = Remove
+Type = Package
+Target = *
+
+[Action]
+Description = Refreshing update-notify...
+When = PostTransaction
+Exec = /usr/lib/update-notify/refresh

update-notify.path

@@ -0,0 +1,10 @@
+[Unit]
+Description=Run update-notify when a local repository changes
+
+# Add the repository files to watch with: systemctl --user edit update-notify.path
+# e.g. PathChanged=/home/aur-local/aur-local.db.tar.gz.sig
+[Path]
+Unit=update-notify.service
+
+[Install]
+WantedBy=default.target