implemented backindex

user/apars_csi.c

@@ -562,6 +562,14 @@ do_csi_set_option(CSI_Data *opts)
 		else if (n == 20) {
 			screen_set_newline_mode(yn);
 		}
+		else if (n == 33) {
+			ansi_noimpl("Steady cursor");
+			// reference https://ttssh2.osdn.jp/manual/en/about/ctrlseq.html
+		}
+		else if (n == 34) {
+			ansi_noimpl("Underline cursor");
+			// reference https://ttssh2.osdn.jp/manual/en/about/ctrlseq.html
+		}
 		else {
 			ansi_noimpl("OPTION %d", n);
 		}

user/apars_osc.c

@@ -22,7 +22,6 @@
 void ICACHE_FLASH_ATTR
 apars_handle_osc(const char *buffer)
 {
-	const char *orig_buff = buffer;
 	int n = 0;
 	char c = 0;
 	while ((c = *buffer++) != 0) {
@@ -50,7 +49,7 @@ apars_handle_osc(const char *buffer)
 		}
 	}
 	else {
-		ansi_warn("BAD OSC: %s", orig_buff);
+		ansi_warn("BAD OSC: %s", buffer);
 		apars_show_context();
 	}
 }

user/apars_short.c

@@ -121,6 +121,10 @@ void ICACHE_FLASH_ATTR apars_handle_short_cmd(char c)
 			screen_reset();
 			break;
 
+		case '6': // back index
+			screen_back_index(1);
+			break;
+
 		case '7': // save cursor + attributes
 			screen_cursor_save(true);
 			break;

user/screen.c

@@ -919,6 +919,21 @@ screen_cursor_restore(bool withAttrs)
 
 	NOTIFY_DONE();
 }
+
+void ICACHE_FLASH_ATTR
+screen_back_index(int count)
+{
+	NOTIFY_LOCK();
+	int new_x = cursor.x - count;
+	if (new_x >= 0) {
+		cursor.x = new_x;
+	} else {
+		cursor.x = 0;
+		screen_insert_characters(-new_x);
+	}
+	NOTIFY_DONE();
+}
+
 //endregion
 
 //region --- Attribute setting ---

user/screen.h

@@ -254,6 +254,8 @@ void screen_clear_tab(void);
 void screen_tab_forward(int count);
 /** Move backward one tab */
 void screen_tab_reverse(int count);
+/** Move left, shift right if at the boundary */
+void screen_back_index(int count);
 
 // --- Printing characters ---