Clang-format all staged changes in a git repository

clang-format-stage

#!/bin/bash

blobs=$(mktemp)
git status --porcelain=v2 -uno > $blobs

while read _ _ _ _ _ filemode oldHash newHash filename; do

  # Skip the file if the staged blob has not changed
  if [ $oldHash == $newHash ]; then
    continue
  fi
  
  # Skip the file if it is not a c++ source file
  if [[ ! $filename =~ ^.*[.cpp|.hpp] ]]; then
     continue
  fi
  
  # Dump the source file
  oldContent=$(mktemp)
  git cat-file -p $newHash > $oldContent
  
  # Format the source file
  newContent=$(mktemp)
  clang-format -style=file $oldContent > $newContent
  
  # Go to the next file, if the code was already formatted correctly
  if cmp $oldContent $newContent; then
    continue
  fi
  
  # Print the changes
  # git --no-pager diff --no-index $oldContent $newContent
  
  # Register the formatted source file in the repository
  newHash2=$(git hash-object -w $newContent)
  
  # Update the stage to the new blob
  git update-index --add --cacheinfo $filemode $newHash2 $filename
  
  echo "Changed file $filename"
  
done < $blobs