--- lbbs/src/str_process.c	2025/06/02 15:01:55	1.11
+++ lbbs/src/str_process.c	2025/11/07 14:22:31	1.26
@@ -1,26 +1,76 @@
-/***************************************************************************
-						  str_process.c  -  description
-							 -------------------
-	Copyright            : (C) 2004-2025 by Leaflet
-	Email                : leaflet@leafok.com
- ***************************************************************************/
-
-/***************************************************************************
- *                                                                         *
- *   This program is free software; you can redistribute it and/or modify  *
- *   it under the terms of the GNU General Public License as published by  *
- *   the Free Software Foundation; either version 3 of the License, or     *
- *   (at your option) any later version.                                   *
- *                                                                         *
- ***************************************************************************/
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * str_process
+ *   - common string processing features with UTF-8 support
+ *
+ * Copyright (C) 2004-2025  Leaflet <leaflet@leafok.com>
+ */
 
-#include "str_process.h"
 #include "common.h"
 #include "log.h"
+#include "str_process.h"
+#include <ctype.h>
 #include <stdio.h>
 #include <string.h>
 
-int split_line(const char *buffer, int max_display_len, int *p_eol, int *p_display_len)
+int str_length(const char *str, int skip_ctrl_seq)
+{
+	int i;
+	char c;
+	int ret = 0;
+
+	for (i = 0; str[i] != '\0'; i++)
+	{
+		c = str[i];
+
+		if (c == '\r' || c == '\7') // skip
+		{
+			continue;
+		}
+
+		if (skip_ctrl_seq && c == '\033' && str[i + 1] == '[') // Skip control sequence
+		{
+			for (i = i + 2; isdigit(str[i]) || str[i] == ';' || str[i] == '?'; i++)
+				;
+
+			if (str[i] == 'm') // valid
+			{
+				// skip
+			}
+			else if (isalpha(str[i]))
+			{
+				// unsupported ANSI CSI command
+			}
+			else
+			{
+				i--;
+			}
+
+			continue;
+		}
+
+		// Process UTF-8 Chinese characters
+		if (c & 0x80) // head of multi-byte character
+		{
+			c = (c & 0x70) << 1;
+			while (c & 0x80)
+			{
+				i++;
+				c = (c & 0x7f) << 1;
+			}
+
+			ret += 2;
+		}
+		else
+		{
+			ret++;
+		}
+	}
+
+	return ret;
+}
+
+int split_line(const char *buffer, int max_display_len, int *p_eol, int *p_display_len, int skip_ctrl_seq)
 {
 	int i;
 	*p_eol = 0;
@@ -36,14 +86,7 @@ int split_line(const char *buffer, int m
 			continue;
 		}
 
-		if (c == '\n')
-		{
-			i++;
-			*p_eol = 1;
-			break;
-		}
-
-		if (c == '\033' && buffer[i + 1] == '[') // Skip control sequence
+		if (skip_ctrl_seq && c == '\033' && buffer[i + 1] == '[') // Skip control sequence
 		{
 			i += 2;
 			while (buffer[i] != '\0' && buffer[i] != 'm')
@@ -53,13 +96,20 @@ int split_line(const char *buffer, int m
 			continue;
 		}
 
-		if (c < 0 || c > 127) // GBK chinese character
+		if (c & 0x80) // head of multi-byte character
 		{
 			if (*p_display_len + 2 > max_display_len)
 			{
 				break;
 			}
-			i++;
+
+			c = (c & 0x70) << 1;
+			while (c & 0x80)
+			{
+				i++;
+				c = (c & 0x7f) << 1;
+			}
+
 			(*p_display_len) += 2;
 		}
 		else
@@ -69,41 +119,81 @@ int split_line(const char *buffer, int m
 				break;
 			}
 			(*p_display_len)++;
+
+			// \n is regarded as 1 character wide in terminal editor, which is different from Web version
+			if (c == '\n')
+			{
+				i++;
+				*p_eol = 1;
+				break;
+			}
 		}
 	}
 
 	return i;
 }
 
-long split_data_lines(const char *p_buf, int max_display_len, long *p_line_offsets, long line_offsets_count)
+long split_data_lines(const char *p_buf, int max_display_len, long *p_line_offsets, long line_offsets_count,
+					  int skip_ctrl_seq, int *p_line_widths)
 {
 	int line_cnt = 0;
-	int len = 0;
+	int len;
 	int end_of_line = 0;
 	int display_len = 0;
 
 	p_line_offsets[line_cnt] = 0L;
 
-	while (1)
+	do
 	{
-		len = split_line(p_buf, max_display_len, &end_of_line, &display_len);
+		len = split_line(p_buf, max_display_len, &end_of_line, &display_len, skip_ctrl_seq);
 
-		if (len == 0) // EOF
+		if (p_line_widths)
 		{
-			break;
+			p_line_widths[line_cnt] = display_len;
 		}
 
 		// Exceed max_line_cnt
 		if (line_cnt + 1 >= line_offsets_count)
 		{
-			log_error("Line count %d reaches limit %d\n", line_cnt + 1, line_offsets_count);
+			// log_error("Line count %d reaches limit %d\n", line_cnt + 1, line_offsets_count);
 			return line_cnt;
 		}
 
 		p_line_offsets[line_cnt + 1] = p_line_offsets[line_cnt] + len;
 		line_cnt++;
 		p_buf += len;
-	}
+	} while (p_buf[0] != '\0');
 
 	return line_cnt;
 }
+
+int str_filter(char *buffer, int skip_ctrl_seq)
+{
+	int i;
+	int j;
+
+	for (i = 0, j = 0; buffer[i] != '\0'; i++)
+	{
+		if (buffer[i] == '\r' || buffer[i] == '\7') // skip
+		{
+			continue;
+		}
+
+		if (skip_ctrl_seq && buffer[i] == '\033' && buffer[i + 1] == '[') // Skip control sequence
+		{
+			i += 2;
+			while (buffer[i] != '\0' && buffer[i] != 'm')
+			{
+				i++;
+			}
+			continue;
+		}
+
+		buffer[j] = buffer[i];
+		j++;
+	}
+
+	buffer[j] = '\0';
+
+	return j;
+}