git-blame-stats.sh

#!/bin/bash

if [ -z "$1" ]; then
  echo Error: please specify a file >&2
  exit 1
fi

for f in $@; do
  if [ ! -f "$f" ]; then
    echo "Error: file '$f' does not exist" >&2
    exit 2
  fi

  lines=`cat "$f" | wc -l`

  echo "Blame stats for $f"
  echo "Percentage   Lines       Author"
  echo ============================================
  git blame --line-porcelain "$f" | sed -n 's/^author //p' | sort | uniq -c | sort -rn | awk -v lines=$lines '{ percentage = 100/lines*$1; sub(/^[ \t]+/,"", $0); sub(/[ \t]+$/,"", $0); printf "%5.2f %%      %4d l     ", percentage, $1; $1 = ""; print $0; }'
  echo ============================================
  echo Lines of file $lines
  echo
done