use notify-send if available

Signed-off-by: fbt <fbt@fleshless.org>

sx-open

@@ -18,6 +18,18 @@ act() {
 	return 0
 }
 
+notify() {
+	[[ $DISPLAY ]] || return 3
+	[[ $notifier ]] || return 5
+
+	"${notifier[@]}" 'sx-open' "$@"
+}
+
+error() {
+	printf '%s\n' "$*" >&2
+	notify "$*"
+}
+
 # handle_target <res> <uri>
 # 1: cmd failed
 # 3: no handler
@@ -122,21 +134,27 @@ main() {
 	# Treat file:// as local paths.
 	[[ "$target" =~ ^file:(//)?(/.+) ]] && target=${BASH_REMATCH[2]}
 
+	# Figure out if we're in X and set $notifier if we are.
+	if [[ $DISPLAY ]]; then
+		# Do we have notify-send?
+		notifier=$(type -P 'notify-send')
+	fi
+
 	handle_target cmd_result "$target"
 
 	case $? in
 		(1)
-			printf 'Action failed with exit code: “%s”\n' "$cmd_result" >&2
+			error "Action on “$target” failed with exit code: “$cmd_result”"
 			return 4
 		;;
 
 		(2)
-			printf 'No such file or directory: “%s”\n' "$target" >&2
+			error "No such file or directory: “$target”"
 			return 2
 		;;
 
 		(3)
-			printf 'No handlers found for “%s”\n' "$target" >&2
+			error "No handlers found for “$target”"
 			return 3
 		;;
 	esac