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README.md

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+# CpkPatcher
+Tool for patching a Criware CPK archive by updating file data without repacking the entire CPK.
+
+# Features
+- Loads and patches a CPK with files from a patch directory.
+
+- Any files existing in the CPK that are not found in the patch directory will remain unmodified. Any unpatched files that had compression will remain compressed.
+
+- Supports patching nested CPKs with `--check-for-nested`. Any folder which exists in the main CPK as a CPK will be loaded and patched.
+
+    ### Example:
+
+    For the following CPK structure
+    ```
+    .
+    └── main.cpk/
+        ├── file1
+        └── sub.cpk/
+            └── file2
+    ```
+
+    A patch directory for patching `file1` and `file2` should look like this
+    ```
+    .
+    └── <patch_directory>/
+        ├── file1
+        └── sub/
+            └── file2
+    ```
+
+# Usage
+Basic usage: `CpkPatcher <path_to_source_cpk> <path_to_patch_directory> <output_cpk_path>`
+
+Full help message:
+
+```
+Usage: CpkPatcher [--help] [--version] [--report-progress] [--report-errors] [--check-for-nested] [--overwrite] source_cpk patch_directory output_cpk
+
+CpkPatcher v1.0
+Patches a CPK by updating file data without repacking the entire CPK
+
+Positional arguments:
+  source_cpk              Path to the source cpk
+  patch_directory         Path to the directory containing the patch files
+  output_cpk              Path where the output cpk will be written
+
+Optional arguments:
+  -h, --help              shows help message and exits
+  -v, --version           prints version information and exits
+  -rp, --report-progress  Print a message after patching each file
+  -re, --report-errors    Print a message when a file could not be patched
+  -n, --check-for-nested  Check for nested CPKs while patching and patch them accordingly
+  -ow, --overwrite        Overwrite output CPK if it exists without prompting
+```
+
+# Limitations
+Does not compress patched files, although unpatched files that were previously compressed will remain compressed.
+
+Has the same limitations as the [CPK implementation](https://github.com/eterniti/eternity_common/blob/main/Criware/CpkFile.h).
+Mainly, **files with a GToc table are not supported**.
+
+# License
+Distributed under the MIT License. See `LICENSE.txt` for more information.
+
+# Acknowledgments
+- [argparse](https://github.com/p-ranav/argparse)
+- [eternity_common](https://github.com/eterniti/eternity_common) for the Criware CPK implementation.