--- lbbs/src/editor.c	2025/06/10 06:48:23	1.3
+++ lbbs/src/editor.c	2025/06/11 11:01:07	1.10
@@ -22,6 +22,7 @@
 #include "str_process.h"
 #include <stdlib.h>
 #include <sys/param.h>
+#include <strings.h>
 
 #define _POSIX_C_SOURCE 200809L
 #include <string.h>
@@ -29,6 +30,7 @@
 EDITOR_DATA *editor_data_load(const char *p_data)
 {
 	EDITOR_DATA *p_editor_data;
+	char *p_data_line = NULL;
 	long line_offsets[MAX_EDITOR_DATA_LINES];
 	long current_data_line_length = 0;
 	long i, j;
@@ -64,8 +66,8 @@ EDITOR_DATA *editor_data_load(const char
 			}
 
 			// Allocate new data line
-			p_editor_data->p_data_lines[p_editor_data->data_line_total] = malloc(MAX_EDITOR_DATA_LINE_LENGTH);
-			if (p_editor_data->p_data_lines[p_editor_data->data_line_total] == NULL)
+			p_data_line = malloc(MAX_EDITOR_DATA_LINE_LENGTH);
+			if (p_data_line == NULL)
 			{
 				log_error("malloc(MAX_EDITOR_DATA_LINE_LENGTH * %d) error: OOM\n", i);
 				// Cleanup
@@ -76,9 +78,10 @@ EDITOR_DATA *editor_data_load(const char
 				free(p_editor_data);
 				return NULL;
 			}
-
-			p_editor_data->p_display_lines[i] = p_editor_data->p_data_lines[p_editor_data->data_line_total];
+			p_editor_data->p_data_lines[p_editor_data->data_line_total] = p_data_line;
 			(p_editor_data->data_line_total)++;
+
+			p_editor_data->p_display_lines[i] = p_data_line;
 			current_data_line_length = 0;
 		}
 		else
@@ -88,9 +91,12 @@ EDITOR_DATA *editor_data_load(const char
 
 		memcpy(p_editor_data->p_display_lines[i], p_data + line_offsets[i], (size_t)p_editor_data->display_line_lengths[i]);
 		current_data_line_length += p_editor_data->display_line_lengths[i];
-		p_editor_data->p_data_lines[p_editor_data->data_line_total - 1][current_data_line_length] = '\0';
+		p_data_line[current_data_line_length] = '\0';
 	}
 
+	bzero(p_editor_data->p_data_lines + p_editor_data->data_line_total, MAX_EDITOR_DATA_LINES - (size_t)p_editor_data->data_line_total);
+	bzero(p_editor_data->p_display_lines + p_editor_data->display_line_total, MAX_EDITOR_DATA_LINES - (size_t)p_editor_data->display_line_total);
+
 	return p_editor_data;
 }
 
@@ -146,20 +152,13 @@ int editor_data_insert(EDITOR_DATA *p_ed
 {
 	long display_line = *p_display_line;
 	long offset = *p_offset;
-	int done = 0;
-	int len;
-	int display_len;
-	int eol;
-	char *p_data_line;
+	char *p_data_line = NULL;
 	long len_data_line;
 	long offset_data_line;
 	long last_display_line; // of data line
-	char buf_insert[MAX_EDITOR_DATA_LINE_LENGTH];
-	long len_insert;
-	int display_len_insert;
-	char buf_catenate[MAX_EDITOR_DATA_LINE_LENGTH];
-	long len_catenate;
-	long i;
+	long line_offsets[MAX_EDITOR_DATA_LINE_LENGTH + 1];
+	long split_line_total;
+	long i, j;
 
 	if (p_editor_data == NULL || p_last_updated_line == NULL)
 	{
@@ -167,14 +166,10 @@ int editor_data_insert(EDITOR_DATA *p_ed
 		return -1;
 	}
 
-	memcpy(buf_insert, str, (size_t)str_len);
-	buf_insert[str_len] = '\0';
-	len_insert = str_len;
-
 	// Get accurate offset of first character of CJK at offset position
 	for (i = 0; i < offset; i++)
 	{
-		if (p_editor_data->p_display_lines[display_line][i] < 0) // GBK
+		if (p_editor_data->p_display_lines[display_line][i] < 0 || p_editor_data->p_display_lines[display_line][i] > 127) // GBK
 		{
 			i++;
 		}
@@ -213,7 +208,7 @@ int editor_data_insert(EDITOR_DATA *p_ed
 	}
 
 	// Split current data line if over-length
-	if (len_data_line + str_len + 1 > MAX_EDITOR_DATA_LINE_LENGTH)
+	if (len_data_line + str_len + 1 > MAX_EDITOR_DATA_LINE_LENGTH || str[0] == CR)
 	{
 		if (p_editor_data->display_line_total >= MAX_EDITOR_DATA_LINES || p_editor_data->data_line_total >= MAX_EDITOR_DATA_LINES)
 		{
@@ -223,57 +218,48 @@ int editor_data_insert(EDITOR_DATA *p_ed
 		}
 
 		// Allocate new data line
-		p_editor_data->p_data_lines[p_editor_data->data_line_total] = malloc(MAX_EDITOR_DATA_LINE_LENGTH);
-		if (p_editor_data->p_data_lines[p_editor_data->data_line_total] == NULL)
+		p_data_line = malloc(MAX_EDITOR_DATA_LINE_LENGTH);
+		if (p_data_line == NULL)
 		{
 			log_error("malloc(MAX_EDITOR_DATA_LINE_LENGTH) error: OOM\n");
 			return -2;
 		}
+		p_editor_data->p_data_lines[p_editor_data->data_line_total] = p_data_line;
+		(p_editor_data->data_line_total)++;
 
-		if (last_display_line > display_line)
-		{
-			// Copy rest part of current data line (since next display line) to new data line
-			memcpy(p_editor_data->p_data_lines[p_editor_data->data_line_total],
-				   p_editor_data->p_display_lines[display_line + 1],
-				   (size_t)(len_data_line - (p_editor_data->p_display_lines[display_line + 1] - p_data_line)));
-			p_editor_data->p_data_lines[p_editor_data->data_line_total]
-									   [len_data_line - (p_editor_data->p_display_lines[display_line + 1] - p_data_line)] = '\0';
-
-			// Relocate rest display lines (since next one) of current data line
-			p_data_line = p_editor_data->p_display_lines[display_line + 1];
-			for (i = display_line + 1; i <= last_display_line; i++)
-			{
-				p_editor_data->p_display_lines[i] =
-					p_editor_data->p_data_lines[p_editor_data->data_line_total] +
-					(p_editor_data->p_display_lines[i] - p_data_line);
-			}
-		}
-		else // last_display_line == display_line
+		if (offset_data_line + str_len + 1 >= MAX_EDITOR_DATA_LINE_LENGTH || str[0] == CR)
 		{
-			// Insert blank display line pointing to new data line
-			for (i = p_editor_data->display_line_total; i > display_line + 1; i--)
+			if (str[0] == CR)
 			{
-				p_editor_data->p_display_lines[i] = p_editor_data->p_display_lines[i - 1];
-				p_editor_data->display_line_lengths[i] = p_editor_data->display_line_lengths[i - 1];
+				str_len = 0;
 			}
-			p_editor_data->p_display_lines[display_line + 1] = p_editor_data->p_data_lines[p_editor_data->data_line_total];
-			p_editor_data->display_line_lengths[display_line + 1] = 0;
 
-			(p_editor_data->display_line_total)++;
-			last_display_line++;
-		}
+			// Copy str to new data line
+			memcpy(p_data_line, str, (size_t)str_len);
 
-		*p_last_updated_line = p_editor_data->display_line_total;
-		(p_editor_data->data_line_total)++;
+			// Copy rest part of current data line to new data line
+			memcpy(p_data_line + str_len,
+				   p_editor_data->p_display_lines[display_line] + offset,
+				   (size_t)(len_data_line - offset_data_line));
+
+			p_data_line[str_len + len_data_line - offset_data_line] = '\0';
+
+			// Add line ending to current display line (data line)
+			p_editor_data->p_display_lines[display_line][offset] = '\n';
+			p_editor_data->p_display_lines[display_line][offset + 1] = '\0';
+			p_editor_data->display_line_lengths[display_line] = offset + 1;
 
-		if (offset_data_line + str_len + 2 < MAX_EDITOR_DATA_LINE_LENGTH)
+			*p_display_line = display_line + 1;
+			*p_offset = str_len;
+		}
+		else
 		{
-			// Copy rest part of current display line to insert buffer
-			memcpy(buf_insert,
+			// Copy rest part of current data line to new data line
+			memcpy(p_data_line,
 				   p_editor_data->p_display_lines[display_line] + offset,
-				   (size_t)(p_editor_data->display_line_lengths[display_line] - offset));
-			len_insert = (p_editor_data->display_line_lengths[display_line] - offset);
-			buf_insert[len_insert] = '\0';
+				   (size_t)(len_data_line - offset_data_line));
+
+			p_data_line[len_data_line - offset_data_line] = '\0';
 
 			// Append str to current display line
 			memcpy(p_editor_data->p_display_lines[display_line] + offset, str, (size_t)str_len);
@@ -283,141 +269,245 @@ int editor_data_insert(EDITOR_DATA *p_ed
 			p_editor_data->p_display_lines[display_line][offset + str_len + 1] = '\0';
 			p_editor_data->display_line_lengths[display_line] = offset + str_len + 1;
 
-			if (!done)
-			{
-				*p_display_line = display_line;
-				*p_offset = offset + str_len;
-				done = 1;
-			}
+			*p_display_line = display_line;
+			*p_offset = offset + str_len;
 		}
-		else
-		{
-			// Append rest part of current display line to insert buffer
-			memcpy(buf_insert + len_insert,
-				   p_editor_data->p_display_lines[display_line] + offset,
-				   (size_t)(p_editor_data->display_line_lengths[display_line] - offset));
-			len_insert += (p_editor_data->display_line_lengths[display_line] - offset);
-			buf_insert[len_insert] = '\0';
 
-			// Add line ending to current display line (data line)
-			p_editor_data->p_display_lines[display_line][offset] = '\n';
-			p_editor_data->p_display_lines[display_line][offset + 1] = '\0';
-			p_editor_data->display_line_lengths[display_line] = offset + 1;
-		}
+		split_line_total = last_display_line - display_line + 3;
 
+		// Set start display_line for spliting new data line
 		display_line++;
-		offset = 0;
+
+		*p_last_updated_line = p_editor_data->display_line_total;
+	}
+	else // insert str into current data line at offset_data_line
+	{
+		memmove(p_data_line + offset_data_line + str_len, p_data_line + offset_data_line, (size_t)(len_data_line - offset_data_line));
+		memcpy(p_data_line + offset_data_line, str, (size_t)str_len);
+		p_data_line[len_data_line + str_len] = '\0';
+
+		// Set p_data_line to head of current display line
+		p_data_line = p_editor_data->p_display_lines[display_line];
+		split_line_total = last_display_line - display_line + 3;
+
+		*p_display_line = display_line;
+		*p_offset = offset + str_len;
 	}
 
-	for (i = display_line; len_insert > 0 && i <= last_display_line; i++)
+	// Split current data line since beginning of current display line
+	split_line_total = split_data_lines(p_data_line, SCREEN_COLS, line_offsets, split_line_total);
+
+	for (i = 0; i < split_line_total; i++)
 	{
-		len = split_line(buf_insert, SCREEN_COLS, &eol, &display_len_insert);
-		if (len != len_insert)
+		if (display_line + i > last_display_line)
 		{
-			log_error("buf_insert is truncated at display_line(%ld): len(%d) != len_insert(%d), buf_insert: %s\n",
-					  i, len, len_insert, buf_insert);
-			return -3;
+			// Insert blank display line after last_display_line
+			if (p_editor_data->display_line_total >= MAX_EDITOR_DATA_LINES)
+			{
+				log_error("display_line_total over limit %d >= %d\n", p_editor_data->display_line_total, MAX_EDITOR_DATA_LINES);
+				return -3;
+			}
+			for (j = p_editor_data->display_line_total; j > last_display_line + 1; j--)
+			{
+				p_editor_data->p_display_lines[j] = p_editor_data->p_display_lines[j - 1];
+				p_editor_data->display_line_lengths[j] = p_editor_data->display_line_lengths[j - 1];
+			}
+			last_display_line++;
+			(p_editor_data->display_line_total)++;
 		}
 
-		memcpy(buf_catenate, p_editor_data->p_display_lines[i], (size_t)p_editor_data->display_line_lengths[i]);
-		buf_catenate[p_editor_data->display_line_lengths[i]] = '\0';
+		p_editor_data->display_line_lengths[display_line + i] = line_offsets[i + 1] - line_offsets[i];
+		p_editor_data->p_display_lines[display_line + i] =
+			(i == 0
+				 ? p_data_line
+				 : (p_editor_data->p_display_lines[display_line + i - 1] + p_editor_data->display_line_lengths[display_line + i - 1]));
 
-		len = split_line(buf_catenate, SCREEN_COLS - display_len_insert, &eol, &display_len);
-		if (len < offset) // offset out of current display line
+		if (p_editor_data->display_line_lengths[display_line + i] > 0 &&
+			p_editor_data->p_display_lines[display_line + i][p_editor_data->display_line_lengths[display_line + i] - 1] == '\n')
 		{
-			offset -= len;
-			continue;
+			break;
 		}
+	}
 
-		// move \n to next display line if current line is full
-		if (len > 0 && buf_catenate[len - 1] == '\n' && display_len + display_len_insert >= SCREEN_COLS)
-		{
-			len--;
-		}
+	*p_last_updated_line = MAX(display_line + MIN(i, split_line_total - 1), *p_last_updated_line);
 
-		memcpy(buf_catenate, p_editor_data->p_display_lines[i], (size_t)offset);
-		memcpy(buf_catenate + offset, buf_insert, (size_t)len_insert);
-		memcpy(buf_catenate + offset + len_insert, p_editor_data->p_display_lines[i] + offset, (size_t)(len - offset));
-		len_catenate = len_insert + len;
-		buf_catenate[len_catenate] = '\0';
+	if (*p_offset > p_editor_data->display_line_lengths[*p_display_line] ||
+		(*p_offset > 0 && *p_offset == p_editor_data->display_line_lengths[*p_display_line] &&
+		 p_editor_data->p_display_lines[*p_display_line][*p_offset - 1] == '\n'))
+	{
+		*p_offset -= p_editor_data->display_line_lengths[*p_display_line];
+		(*p_display_line)++;
 
-		len_insert = p_editor_data->display_line_lengths[i] - len;
-		if (len_insert > 0)
+		if (*p_display_line >= p_editor_data->display_line_total)
 		{
-			memcpy(buf_insert, p_editor_data->p_display_lines[i] + len, (size_t)len_insert);
-			buf_insert[len_insert] = '\0';
+			log_error("*p_display_line(%d) >= display_line_total(%d)\n", *p_display_line, p_editor_data->display_line_total);
 		}
+	}
+
+	return 0;
+}
 
-		memcpy(p_editor_data->p_display_lines[i], buf_catenate, (size_t)len_catenate);
-		p_editor_data->display_line_lengths[i] = len_catenate;
+int editor_data_delete(EDITOR_DATA *p_editor_data, long display_line, long offset,
+					   long *p_last_updated_line)
+{
+	char *p_data_line = NULL;
+	long len_data_line;
+	long offset_data_line;
+	long last_display_line; // of data line
+	long line_offsets[MAX_EDITOR_DATA_LINE_LENGTH + 1];
+	long split_line_total;
+	long i, j;
+	int str_len = 0;
 
-		if (!done)
+	if (p_editor_data == NULL || p_last_updated_line == NULL)
+	{
+		log_error("editor_data_op() error: NULL pointer\n");
+		return -1;
+	}
+
+	// Get accurate offset of first character of CJK at offset position
+	for (i = 0; i < offset; i++)
+	{
+		if (p_editor_data->p_display_lines[display_line][i] < 0 || p_editor_data->p_display_lines[display_line][i] > 127) // GBK
 		{
-			*p_display_line = i;
-			*p_offset = offset + str_len;
-			done = 1;
+			i++;
 		}
-
-		offset = 0;
+	}
+	if (i > offset) // offset was skipped
+	{
+		offset--;
 	}
 
-	*p_last_updated_line = MAX(i, *p_last_updated_line);
+	// Get length of current data line
+	len_data_line = 0;
+	p_data_line = p_editor_data->p_display_lines[display_line];
+	for (i = display_line - 1; i >= 0; i--)
+	{
+		if (p_editor_data->display_line_lengths[i] > 0 &&
+			p_editor_data->p_display_lines[i][p_editor_data->display_line_lengths[i] - 1] == '\n') // reach end of prior data line
+		{
+			break;
+		}
 
-	if (len_insert > 0)
+		len_data_line += p_editor_data->display_line_lengths[i];
+		p_data_line = p_editor_data->p_display_lines[i];
+	}
+	offset_data_line = len_data_line + offset;
+	last_display_line = p_editor_data->display_line_total - 1;
+	for (i = display_line; i < p_editor_data->display_line_total; i++)
 	{
-		if (p_editor_data->display_line_total >= MAX_EDITOR_DATA_LINES)
+		len_data_line += p_editor_data->display_line_lengths[i];
+
+		if (p_editor_data->display_line_lengths[i] > 0 &&
+			p_editor_data->p_display_lines[i][p_editor_data->display_line_lengths[i] - 1] == '\n') // reach end of current data line
 		{
-			log_error("Append line error, display_line_total(%ld) reach limit(%d)\n",
-					  p_editor_data->display_line_total, MAX_EDITOR_DATA_LINES);
-			return -2;
+			last_display_line = i;
+			break;
 		}
+	}
 
-		// Prepare one blank display line after last_display_line
-		for (i = p_editor_data->display_line_total; i > last_display_line + 1; i--)
+	// Check str to be deleted
+	if (p_data_line[offset_data_line] > 0 && p_data_line[offset_data_line] < 127)
+	{
+		str_len = 1;
+	}
+	else if (p_data_line[offset_data_line + 1] < 0 || p_data_line[offset_data_line] > 127) // GBK
+	{
+		str_len = 2;
+	}
+	else
+	{
+		log_error("Some strange character at display_line %ld, offset %ld: %d %d %d %d\n",
+				  display_line, offset, p_data_line[offset_data_line], p_data_line[offset_data_line + 1],
+				  p_data_line[offset_data_line + 2], p_data_line[offset_data_line + 3]);
+		str_len = 1;
+	}
+
+	// Current display line is (almost) empty
+	if (offset_data_line + str_len > len_data_line ||
+		(offset_data_line + str_len == len_data_line && p_data_line[offset_data_line] == '\n'))
+	{
+		if (display_line + 1 >= p_editor_data->display_line_total) // No additional display line (data line)
 		{
-			p_editor_data->p_display_lines[i] = p_editor_data->p_display_lines[i - 1];
-			p_editor_data->display_line_lengths[i] = p_editor_data->display_line_lengths[i - 1];
+			log_common("Debug: No additional display line: %ld + 1 >= %ld\n", display_line, p_editor_data->display_line_total);
+			return 0;
 		}
-		p_editor_data->p_display_lines[last_display_line + 1] =
-			p_editor_data->p_display_lines[last_display_line] + p_editor_data->display_line_lengths[last_display_line];
-		p_editor_data->display_line_lengths[last_display_line + 1] = 0;
 
-		(p_editor_data->display_line_total)++;
-		last_display_line++;
+		len_data_line = 0; // Next data line
+		last_display_line = p_editor_data->display_line_total - 1;
+		for (i = display_line + 1; i < p_editor_data->display_line_total; i++)
+		{
+			len_data_line += p_editor_data->display_line_lengths[i];
 
-		// Fill data into blank display line
-		memcpy(p_editor_data->p_display_lines[last_display_line], buf_insert, (size_t)len_insert);
-		p_editor_data->p_display_lines[last_display_line][len_insert] = '\0';
-		p_editor_data->display_line_lengths[last_display_line] = len_insert;
+			if (p_editor_data->display_line_lengths[i] > 0 &&
+				p_editor_data->p_display_lines[i][p_editor_data->display_line_lengths[i] - 1] == '\n') // reach end of current data line
+			{
+				last_display_line = i;
+				break;
+			}
+		}
 
-		if (!done)
+		if (offset_data_line + len_data_line + 1 > MAX_EDITOR_DATA_LINE_LENGTH) // No enough buffer to merge current data line with next data line
 		{
-			*p_display_line = last_display_line;
-			*p_offset = str_len;
-			done = 1;
+			log_common("Debug: No enough buffer to merge with next data line: %ld > %ld\n",
+					   offset_data_line + len_data_line + 1, MAX_EDITOR_DATA_LINE_LENGTH);
+			return 0;
 		}
 
-		*p_last_updated_line = MAX(last_display_line, *p_last_updated_line);
+		// Append next data line to current one
+		memcpy(p_data_line + offset_data_line, p_editor_data->p_display_lines[display_line + 1], (size_t)len_data_line);
+		p_data_line[offset_data_line + len_data_line] = '\0';
+
+		// Recycle next data line
+		// TODO: free(p_editor_data->p_display_lines[display_line + 1]);
+	}
+	else
+	{
+		memmove(p_data_line + offset_data_line, p_data_line + offset_data_line + str_len, (size_t)(len_data_line - offset_data_line - str_len));
+		p_data_line[len_data_line - str_len] = '\0';
+		len_data_line -= str_len;
 	}
 
-	if (done && *p_offset >= SCREEN_COLS)
+	// Set p_data_line to head of current display line
+	p_data_line = p_editor_data->p_display_lines[display_line];
+	split_line_total = last_display_line - display_line + 2;
+
+	// Split current data line since beginning of current display line
+	split_line_total = split_data_lines(p_data_line, SCREEN_COLS, line_offsets, split_line_total);
+
+	for (i = 0; i < split_line_total; i++)
 	{
-		(*p_display_line)++;
-		*p_offset = 0;
+		p_editor_data->display_line_lengths[display_line + i] = line_offsets[i + 1] - line_offsets[i];
+		p_editor_data->p_display_lines[display_line + i] =
+			(i == 0
+				 ? p_data_line
+				 : (p_editor_data->p_display_lines[display_line + i - 1] + p_editor_data->display_line_lengths[display_line + i - 1]));
 
-		if (*p_display_line >= p_editor_data->display_line_total)
+		if (p_editor_data->display_line_lengths[display_line + i] > 0 &&
+			p_editor_data->p_display_lines[display_line + i][p_editor_data->display_line_lengths[display_line + i] - 1] == '\n')
 		{
-			log_error("*p_display_line(%d) >= display_line_total(%d)\n", *p_display_line, p_editor_data->display_line_total);
+			break;
 		}
 	}
 
-	return done;
-}
+	*p_last_updated_line = display_line + MIN(i, split_line_total - 1);
 
-int editor_data_delete(EDITOR_DATA *p_editor_data, long display_line, long offset,
-					   long *p_last_updated_line)
-{
-	return 0;
+	if (display_line + i < last_display_line)
+	{
+		// Remove redundant display line after last_display_line
+		for (j = last_display_line + 1; j < p_editor_data->display_line_total; j++)
+		{
+			p_editor_data->p_display_lines[j - (last_display_line - (display_line + i))] = p_editor_data->p_display_lines[j];
+			p_editor_data->display_line_lengths[j - (last_display_line - (display_line + i))] = p_editor_data->display_line_lengths[j];
+		}
+
+		(p_editor_data->display_line_total) -= (last_display_line - (display_line + i));
+		last_display_line = display_line + i;
+
+		*p_last_updated_line = p_editor_data->display_line_total - 1;
+	}
+
+	return str_len;
 }
 
 static int editor_display_key_handler(int *p_key, EDITOR_CTX *p_ctx)
@@ -439,7 +529,7 @@ int editor_display(EDITOR_DATA *p_editor
 	char buffer[MAX_EDITOR_DATA_LINE_LENGTH];
 	EDITOR_CTX ctx;
 	int ch = 0;
-	char insert_str[4];
+	char input_str[4];
 	int str_len = 0;
 	int input_ok;
 	int screen_current_row;
@@ -455,7 +545,7 @@ int editor_display(EDITOR_DATA *p_editor
 	long display_line_out, offset_out;
 	int scroll_rows;
 	long last_updated_line = 0;
-	int insert = 1;
+	int key_insert = 1;
 	int i;
 
 	screen_current_row = screen_begin_row;
@@ -476,10 +566,11 @@ int editor_display(EDITOR_DATA *p_editor
 
 			snprintf(buffer, sizeof(buffer),
 					 "\033[1;44;33m[\033[32m%ld\033[33m;\033[32m%ld\033[33m] "
-					 "第\033[32m%ld\033[33m/\033[32m%ld\033[33m行 "
+					 "第\033[32m%ld\033[33m/\033[32m%ld\033[33m行 [\033[32m%s\033[33m] "
 					 "%s",
 					 row_pos, col_pos,
 					 ctx.line_cursor, p_editor_data->display_line_total,
+					 key_insert ? "插入" : "改写",
 					 ctx.msg);
 
 			len = split_line(buffer, SCREEN_COLS, &eol, &display_len);
@@ -510,7 +601,7 @@ int editor_display(EDITOR_DATA *p_editor
 
 				if (ch > 127 && ch <= 255) // GBK
 				{
-					insert_str[str_len] = (char)(ch - 256);
+					input_str[str_len] = (char)(ch - 256);
 					str_len++;
 				}
 				else
@@ -518,11 +609,11 @@ int editor_display(EDITOR_DATA *p_editor
 					str_len = 0;
 				}
 
-				if ((ch >= 32 && ch < 127) || (ch > 127 && ch <= 255 && str_len == 2)) // printable character or GBK
+				if ((ch >= 32 && ch < 127) || (ch > 127 && ch <= 255 && str_len == 2) || ch == CR) // printable character or GBK
 				{
 					if (str_len == 0)
 					{
-						insert_str[0] = (char)ch;
+						input_str[0] = (char)ch;
 						str_len = 1;
 					}
 
@@ -532,10 +623,19 @@ int editor_display(EDITOR_DATA *p_editor
 					display_line_out = display_line_in;
 					offset_out = offset_in;
 
+					if (!key_insert) // overwrite
+					{
+						if (editor_data_delete(p_editor_data, display_line_in, offset_in,
+											   &last_updated_line) < 0)
+						{
+							log_error("editor_data_delete() error\n");
+						}
+					}
+
 					if (editor_data_insert(p_editor_data, &display_line_out, &offset_out,
-										   insert_str, str_len, &last_updated_line) < 0)
+										   input_str, str_len, &last_updated_line) < 0)
 					{
-						log_error("editor_data_insert(%s) error\n", insert_str);
+						log_error("editor_data_insert(%s) error\n", input_str);
 						str_len = 0;
 					}
 					else
@@ -574,18 +674,48 @@ int editor_display(EDITOR_DATA *p_editor
 						continue;
 					}
 				}
-				else if (ch == KEY_DEL) // Del
+				else if (ch == KEY_DEL || ch == BACKSPACE) // Del
 				{
-					last_updated_line = line_current;
+					if (ch == BACKSPACE)
+					{
+						col_pos--;
+						if (col_pos < 1 && line_current - screen_current_row + row_pos >= 0)
+						{
+							row_pos--;
+							col_pos = MAX(1, p_editor_data->display_line_lengths[line_current - screen_current_row + row_pos]);
+						}
+					}
 
-					if (editor_data_delete(p_editor_data, line_current - screen_current_row + row_pos, col_pos - 1,
-										   &last_updated_line) < 0)
+					if ((str_len = editor_data_delete(p_editor_data, line_current - screen_current_row + row_pos, col_pos - 1,
+													  &last_updated_line)) < 0)
 					{
 						log_error("editor_data_delete() error\n");
 					}
 					else
 					{
+						if (ch == BACKSPACE)
+						{
+							for (i = 1; i < str_len; i++)
+							{
+								col_pos--;
+								if (col_pos < 1 && line_current - screen_current_row + row_pos >= 0)
+								{
+									row_pos--;
+									col_pos = MAX(1, p_editor_data->display_line_lengths[line_current - screen_current_row + row_pos]);
+								}
+							}
+						}
+
 						screen_end_row = MIN(SCREEN_ROWS - 1, screen_current_row + (int)(last_updated_line - line_current));
+						line_current -= (screen_current_row - row_pos);
+						screen_current_row = (int)row_pos;
+
+						if (screen_current_row < screen_begin_row) // row_pos <= 0
+						{
+							screen_current_row = screen_begin_row;
+							row_pos = screen_begin_row;
+							screen_end_row = SCREEN_ROWS - 1;
+						}
 					}
 
 					continue;
@@ -614,7 +744,7 @@ int editor_display(EDITOR_DATA *p_editor
 					col_pos = MIN(col_pos, MAX(1, p_editor_data->display_line_lengths[line_current - screen_current_row + row_pos]));
 					break;
 				case KEY_INS:
-					insert = !insert;
+					key_insert = !key_insert;
 					break;
 				case KEY_HOME:
 					row_pos = 1;
@@ -668,8 +798,6 @@ int editor_display(EDITOR_DATA *p_editor
 					screen_end_row = SCREEN_ROWS - 1; // Legacy Fterm only works with this line
 					col_pos = MIN(col_pos, MAX(1, p_editor_data->display_line_lengths[line_current - screen_current_row + row_pos]));
 					break;
-				case CR:
-					break;
 				case KEY_SPACE:
 					break;
 				case KEY_RIGHT: