mpatch Skill
Smart context-aware CLI tool for applying unified diffs with fuzzy matching.
When to Use
- Applying unified diff patches to source files via command line
- Patches where line numbers may be outdated
- Fuzzy matching patches against modified content
- Processing Markdown diff blocks, unified diffs, or conflict markers
Installation
cargo install mpatch
CLI Usage
Basic Syntax
mpatch <INPUT_FILE> <TARGET_DIR>
Arguments
| Argument | Description |
|---|---|
INPUT_FILE | Path to patch file (Markdown, Unified Diff, or Conflict Markers) |
TARGET_DIR | Directory containing files to patch |
Options
| Option | Description |
|---|---|
-n, --dry-run | Show what would be done without modifying files |
-f, --fuzz-factor <0.0-1.0> | Similarity threshold for fuzzy matching (default: 0.7). Higher = stricter. 0 = disable fuzzy |
-v, --verbose | Increase verbosity: -v info, -vv debug, -vvv trace, -vvvv debug report |
-h, --help | Print help |
-V, --version | Print version |
Examples
Apply a patch
mpatch changes.patch ./src
Dry run (preview changes)
mpatch -n changes.patch ./src
Strict matching (no fuzzy)
mpatch -f 0 changes.patch ./src
Lenient fuzzy matching
mpatch -f 0.5 changes.patch ./src
Verbose output for debugging
mpatch -vv changes.patch ./src
Supported Patch Formats
mpatch auto-detects the input format:
-
Unified Diff (standard
diff -uoutput)--- a/file.txt +++ b/file.txt @@ -1,3 +1,4 @@ line1 +new line line2 -
Markdown Code Blocks (common in AI-generated patches)
```diff --- a/file.txt +++ b/file.txt @@ -1,3 +1,4 @@ context -old +new ``` -
Conflict Markers (git merge conflicts)
<<<<<<< HEAD current content ======= incoming content >>>>>>> branch
Key Features
- Ignores line numbers: Uses context matching instead
- Fuzzy matching: Applies patches even when source has minor changes
- Auto-detection: No need to specify patch format
- Smart indentation: Handles indentation differences
Common Mistakes
| Mistake | Fix |
|---|---|
| Forgetting target directory | Second argument is the directory, not the file |
| Expecting exact match | Use -f 0 if you want strict matching |
| Not checking results first | Use -n (dry-run) to preview |
| Patch not applying | Try -f 0.5 for more lenient matching |
Workflow Example
# 1. Preview what will change
mpatch -n patch.diff ./myproject
# 2. Apply with verbose output
mpatch -v patch.diff ./myproject
# 3. If fuzzy fails, try more lenient
mpatch -f 0.5 patch.diff ./myproject