--- lbbs/utils/lib/str_process.inc.php	2025/05/03 14:52:26	1.1
+++ lbbs/utils/lib/str_process.inc.php	2025/07/02 04:17:33	1.3
@@ -1,5 +1,5 @@
 <?php
-function str_length(string $str) : string
+function str_length(string $str) : int
 {
 	$len = strlen($str);
 	$ret = 0;
@@ -8,12 +8,17 @@ function str_length(string $str) : strin
 	{
 		$c = $str[$i];
 
-		// Process GBK Chinese characters
+		// Process UTF-8 Chinese characters
 		$v1 = ord($c);
-		if ($v1 > 127 && $v1 <= 255) // GBK chinese character
+		if ($v1 & 0b10000000) //head of multi-byte character
 		{
-			$i++;
-			$c .= $str[$i];
+			$v2 = ($v1 & 0b01110000) << 1;
+			while ($v2 & 0b10000000)
+			{
+				$i++;
+				$c .= $str[$i];
+				$v2 = ($v2 & 0b01111111) << 1;
+			}
 
 			$ret += 2;
 		}
@@ -65,14 +70,19 @@ function split_line(string $str, string
 			continue;
 		}
 
-		// Process GBK Chinese characters
+		// Process UTF-8 Chinese characters
 		$v1 = ord($c);
-		if ($v1 > 127 && $v1 <= 255) // GBK chinese character
+		if ($v1 & 0b10000000) //head of multi-byte character
 		{
-			$i++;
-			$c .= $str[$i];
+			$v2 = ($v1 & 0b01110000) << 1;
+			while ($v2 & 0b10000000)
+			{
+				$i++;
+				$c .= $str[$i];
+				$v2 = ($v2 & 0b01111111) << 1;
+			}
 
-			// Each GBK CJK character should use two character length for display
+			// Each UTF-8 CJK character should use two character length for display
 			if ($line_len + 2 > $width)
 			{
 				if ($lines_count + 1 >= $lines_limit)