feat: clear last entry if we get clear from CLIPBOARD_STATE

fixes #58

cliphist.go

@@ -51,13 +51,13 @@ func main_() int {
 	var err error
 	switch flags.Arg(0) {
 	case "store":
-		// from man wl-clipboard
-		switch os.Getenv("CLIPBOARD_STATE") {
+		switch x := os.Getenv("CLIPBOARD_STATE"); x { // from man wl-clipboard
 		case "sensitive":
-			return 0
+		case "clear":
+			err = deleteLast()
+		default:
+			err = store(os.Stdin, *maxDedupeSearch, *maxItems)
 		}
-
-		err = store(os.Stdin, *maxDedupeSearch, *maxItems)
 	case "list":
 		err = list(os.Stdout)
 	case "decode":
@@ -261,6 +261,30 @@ func deleteQuery(query string) error {
 	return nil
 }
 
+func deleteLast() error {
+	db, err := initDB()
+	if err != nil {
+		return fmt.Errorf("opening db: %w", err)
+	}
+	defer db.Close()
+
+	tx, err := db.Begin(true)
+	if err != nil {
+		return fmt.Errorf("begin tx: %w", err)
+	}
+	defer tx.Rollback() //nolint:errcheck
+
+	b := tx.Bucket([]byte(bucketKey))
+	c := b.Cursor()
+	k, _ := c.Last()
+	_ = b.Delete(k)
+
+	if err := tx.Commit(); err != nil {
+		return fmt.Errorf("commit tx: %w", err)
+	}
+	return nil
+}
+
 func delete(in io.Reader) error {
 	input, err := io.ReadAll(in)
 	if err != nil {

testdata/clipboard-state-env-clear.txtar

@@ -0,0 +1,32 @@
+stdin in-1
+exec cliphist store
+stdin in-2
+exec cliphist store
+stdin in-3
+exec cliphist store
+
+exec cliphist list
+cmp stdout out-before
+
+env CLIPBOARD_STATE=clear
+exec cliphist store
+
+exec cliphist list
+cmp stdout out-after
+
+-- in-1 --
+test input 1
+
+-- in-2 --
+test input 2
+
+-- in-3 --
+test input 3
+
+-- out-before --
+3	test input 3
+2	test input 2
+1	test input 1
+-- out-after --
+2	test input 2
+1	test input 1