Get number of lines added and deleted per day from your git repo

git-line-add-delete-per-day.sh

#!/bin/bash

usage() {
  echo "Usage: $0 BRANCH NUM_DAYS"
  exit 1
}

ds() {
  date --date="$1 days ago" +%Y-%m-%d
}

if [ $# -lt 2 ] ; then
  usage
fi

BRANCH=$1
NUM_DAYS=$2

if ! git rev-parse --verify $BRANCH ; then
  echo "Branch with name '$BRANCH' does not exist"
  echo
  usage
fi

echo "Date,LinesAdded,LinesDeleted"
for day in $(seq 1 $NUM_DAYS)
do
  lines=$(git --no-pager log --after=$(ds $day) --before=$(ds $(($day - 1))) --format=format: --numstat $BRANCH | awk '{s+=$1; t+=$2;} END {printf "+%s,-%s",s,t}')
  if [[ "$lines" != "+,-" ]]; then
    echo "$(ds $day),$lines"
  else
    echo "$(ds $day),0,0"
  fi
done