A very very slow one-liner that goes through a git blame and sees how many lines were contributed by each author.

creditwherecreditisdue.sh

git ls-files -z | xargs -0n1 git blame -wfn | grep -v "test" | grep "\.(js|html)[^o]\s" | perl -n -e '/\((.*)\s[\d]{4}\-/ && print $1."\n"' | awk '{print $1" "$2" "$3}' | sort -f | uniq -c | sort -nr

# Lists the number of lines that an author has contributed to the code base.
# This also filters for !test and ==.js or .html (which was useful for this particular run)

# A Django version of the same thing: 
git ls-files -z | xargs -0n1 git blame -wfn | grep -v "test" | grep -v "fixture" | grep -v "json" | grep -v "gpg" | grep -v ".md" | grep -v "initial_schema" | grep -v "fonts" | grep -v "min." | grep -v "migrations" | grep -v "images" | grep -v "/bootstrap" | grep -v "debug" | grep -v "/img" | grep -v "vendor" | perl -n -e '/\((.*)\s[\d]{4}\-/ && print $1."\n"' | awk '{print $1" "$2" "$3}' | sort -f | uniq -c | sort -nr

removemergedbranches.sh

git branch --merged | grep -v `git rev-parse --abbrev-ref HEAD` | xargs git branch -d

# checkout your dev branch, and then clean up your local by running this to remove all merged branches. 

whatdidtheywrite.sh

git ls-files -z | xargs -0n1 git blame -wfn | awk '/<author>/{print $0}'

# I suggest only using this if the author has a small number of lines listed above. 
# I also adjusted it to include the file name and line number. 

whatfilesdidtheychange.sh

git ls-files -z | xargs -0n1 git blame -wfn | awk '/<author>/{print $2}' | sort -f | uniq -c | sort -nr

# Lists out files that have been altered by a given author (including number of lines changed in that file).