GTK Special Characters

The following characters need escaping: &, <, >

You can use g_markup_escape_text() to do it, e.g.:

	strcpy(temp_string, KEYBOARD_TEXT_SPAN_MARKUP);
	strcat(temp_string, g_markup_escape_text(&edit_text[0], -1));		//g_markup_escape_text will escape any special (&, <, >) characters in your string 
	strcat(temp_string, "</span>");
	gtk_label_set_markup(GTK_LABEL(lblKeyboardText), temp_string);

//or

	strcpy(temp_string, KEYBOARD_TEXT_SPAN_MARKUP);
	strcat(temp_string, g_markup_escape_text(MyString.c_str(), -1));		//g_markup_escape_text will escape any special (&, <, >) characters in your string 
	strcat(temp_string, "</span>");
	gtk_label_set_markup(GTK_LABEL(lblKeyboardText), temp_string);