count_git_loc.sh

#!/bin/bash

if [ -z "$1" ]; then
  echo "Usage: $0 <subdirectory>"
  exit 1
fi

SUBDIR="$1"

GIT_ROOT=$(git rev-parse --show-toplevel)
if [ $? -ne 0 ]; then
  echo "Error: The specified directory is not within a Git repository."
  exit 1
fi

count_loc() {
  find "$SUBDIR" -type f -print0 | xargs -0 wc -l | tail -n 1 | awk '{print $1}'
}

cd "$GIT_ROOT" || exit

commits=$(git rev-list --reverse HEAD)

i=0
for commit in $commits; do
  if (( i % 500 == 0 )); then
    git clean -fdq
    git checkout -q "$commit"
    hash=$(git log -1 --format="%H")
    date=$(git log -1 --format="%ad" --date=short)
    loc=$(count_loc)

    echo "$date, $loc"
  fi
  ((i++))
done

git checkout -q master
git clean -fdq