Improve interactive mode.

CHANGELOG.md

@@ -1,6 +1,8 @@
 # Changelog
 
 ## Unreleased
+## Changed
+- Improve interactive mode.
 
 ## [v0.5.4] 2022-09-30
 ### Changed

main.go

@@ -420,10 +420,17 @@ func main() {
 		}
 	case *flagInteractive:
 		// Send in endless loop (for usage with e.g. "tail -f").
+		var reader = bufio.NewReader(os.Stdin)
 		for {
-			scanner := bufio.NewScanner(os.Stdin)
-			scanner.Scan()
-			message = scanner.Text()
+			message, err = reader.ReadString('\n')
+			if err != nil {
+				log.Fatal("failed to read from stdin")
+			}
+
+			// Remove invalid code points.
+			message = strings.ToValidUTF8(message, "")
+			reg := regexp.MustCompile(`[\x{0000}-\x{0008}\x{000B}\x{000C}\x{000E}-\x{001F}]`)
+			message = reg.ReplaceAllString(message, "")
 			if message == "" {
 				continue
 			}