Find backup exlude files in home directores again

usr/local/sbin/restic_backup.sh

@@ -20,13 +20,33 @@ exit_hook() {
 }
 trap exit_hook INT TERM
 
-# Set up exclude files: global + path-specific ones.
+# Set up exclude files: global + path-specific ones + home directoreis.
+# NOTE that restic will fail the backup if not all listed --exclude-files exist. Thus we should only list them if they are really all available.
+##  Global backup configuration.
 exclusion_args="--exclude-file /etc/restic/backup_exclude"
+## Self-contained backup files per backup path. E.g. having an USB disk at /mnt/media in BACKUP_PATHS, then it can have a /mnt/media/.backup_exclude
 for backup_path in ${BACKUP_PATHS[@]}; do
 	if [ -f "$backup_path/.backup_exclude" ]; then
 		exclusion_args+=" --exclude-file $backup_path/.backup_exclude"
 	fi
 done
+## Additonal service: if /home is being backed up, allow user specifci backup files in home directory or default $XDG_CONFIG_HOME path
+backup_files_from_homedirs() {
+	local homeroot="$1"
+	local args=
+	if [[ $BACKUP_PATHS == *"$homeroot"* ]]; then
+		for homedir in $homeroot/*; do
+			excl_home="$homedir/.backup_exclude"
+			excl_xdg="$homedir/.config/restic/backup_exclude"
+			test -f $excl_home && args+=" --exclude-file $excl_home"
+			test -f $excl_xdg && args+=" --exclude-file $excl_xdg"
+		done
+	fi
+	echo $args
+}
+exclusion_args="$exclusion_args $(backup_files_from_homedirs /home)"
+## And the same service of macOS users, having /Users instead of /home
+exclusion_args="$exclusion_args $(backup_files_from_homedirs /Users)"
 
 # NOTE start all commands in background and wait for them to finish.
 # Reason: bash ignores any signals while child process is executing and thus the trap exit hook is not triggered.