打开两个文件，从a文件中选择一段在b文件中寻找，如果找不到，在左侧栏列出。再从b文件中选择一段在a文件中查找，如果查找不到，在b文件中列出。-Open the two files from a file, select a file look in b, if found, are listed in the left column. And from b to select a file in a file, find, if not find, listed in the b file.