This gist is a fast way to get line contributions in git per author.

find-git-contributions.sh

########################################################################
# This gist is a fast way to get line contributions in git per author. #
# The results should not be intepreted seriously, line-contributions   #
# are a weak indicator of the value of someone's contribution.         #
########################################################################

# If you have GNU parallel utility installed (recommended)

git ls-tree --name-only -r HEAD | parallel --eta "git blame -w -M -C --line-porcelain {} | grep \"^author \"" | sort -S 20G | uniq -c | sort -nr

# If you don't have GNU parallel utility installed

git ls-tree --name-only -r HEAD | xargs -n1 git blame -w -M -C --line-porcelain | grep "^author " | sort -S 20G | uniq -c | sort -nr

###############################
# Explanation of the commands #
###############################

# List all the files found in the git HEAD for that directory
git ls-tree --name-only -r HEAD

# For each line find the user who authored it, ignoring whitespaces, and detecting copy-pastes
git blame -w -M -C --line-porcelain

# Extract the author field
grep "^author "

# Sort ALL the author fields (20G is the memory buffer allowed for sorting)
sort -S 20G 

# Count unique lines
uniq -c

# Sort them one more time from their counts
sort -nr