How to compare multi-line diff

[AKclown]

demand：
I want to match based on the number of rows. According to the basis of each line, get the detailed information about deleting/adding/modifying each line

The data information view is as follows：

[bhupiister]

@AKclown Can you try some code or library which was unindent the file and then do the diff or patch operation ? And then indent it back ?