hall_of_blame.sh

#!/bin/bash

# ag is the_silver_searcher (https://github.com/ggreer/the_silver_searcher)

ag TODO | while read line; do
  file=$(echo ${line} | awk -F ':' '{print $1}');
  lineno=$(echo ${line} | awk -F ':' '{print $2}');
  git blame --line-porcelain "./${file}" -L ${lineno},${lineno} | grep author-mail | cut -d ' ' -f 2;
done | sort | uniq -c

# Example output:
#  30 <[email protected]>
#  20 <[email protected]>
#   7 <[email protected]>
#   3 <[email protected]>
#   3 <[email protected]>