wbdiff - Advanced diff utility

Diffing tool with few sophisticated features, hopefully makeing developer’s life
easier.

Example output:

$ ./wbdiff tests/9/left tests/9/right
Removals from left file, moves and additions to right file:
--- tests/9/left
+++ tests/9/right
---------\ l0017-l0022 -> r0001-r0006  (5 lines)
 17->  1 | q
 18->  2 | r
 19->  3 | s
 20->  4 | t
 21->  5 | v
---------/
---------\ l0009-l0014 -> r0006-r0011  (5 lines)
  9->  6 | i
 10->  7 | j
 11->  8 | k
 12->  9 | l
 13-> 10 | m
---------/
   -> 11 + A
   -> 12 + E
---------\ l0001-l0009 -> r0013-r0021  (8 lines)
  1-> 13 | a
  2-> 14 | b
  3-> 15 | c
  4-> 16 | d
  5-> 17 | e
  6-> 18 | f
  7-> 19 | g
  8-> 20 | h
---------/
---------\ l0014-l0017 -> r0021-r0024  (3 lines)
 14-> 21 | n
 15-> 22 | o
 16-> 23 | p
---------/
Diff statistics:
    Initial context length used: 3
    Number of matching (extended) blocks: 4
    Number of lines in matching (extended) blocks: 21
    Number of lines removed from left file: 0
    Number of new lines added to right file: 2
    Weighted cost (blocks + removed + added): 5

Or in colors:

Please notice, the line number in the left most column, and how wbdiff maps
them to the right column, detecting block moves, additions, removals, while some
blocks have minor edits in them.

Features:

• Detection of moved code blocks
• Fuzzy matching on both block and line level
• Adaptative moved blocks and fuzzy matching
• Shortening of long blocks
• Color output
• Statistics at the end of diff output
• Support for reading compressed files transparently (.gz, .bz2)
• Ability to ignore certain types of changes
• Normalization of lines
• Diff algorithm and output tunable using command line options
• git integration support
• Tested by more than dozen of unittests
• Slowness

TODO:

• Splited/merged lines detection
• Recursive diffing of multiple files/directories
• Speed optimizations

History

This tool was created on one evening, when I was utterly annoyed by lack of good
diff tools. I checked about 15 of them, and actually Microsoft’s free version
WinDiff was best (running in WINE)! However, I wanted simple tool, with ability
to work from command line natively on Linux, and more possible customizations.
Then in few hours I created wbdiff.py :) Works perfectly for me, producing
optimal diffs.

Copyright: Witold Baryluk, 2013, 2021