Print list of git authors with total added lines, total removed lines, total lines really added and percent of participation over added lines

gistfile1.txt

git shortlog -s | cut -f2 | while read a; do git log --author="$a" --pretty=tformat: --numstat | awk '{ add += $1 ; subs += $2 ; loc += $1 - $2 } END { print "'"$a"',"add","subs","loc }'; done | awk '{ print; split($0,a,","); total += a[2] } END { print "Total,"total",0,"total }' | sort -nrk2 -t',' | while read l; do a=`echo $l | cut -d',' -f1`; if [ "$a" == "Total" ]; then t=`echo $l | cut -d',' -f2`; fi; mt=`echo $l | cut -d',' -f2`; echo $l","`awk 'BEGIN { printf("%d", '$mt'/'$t'*100) }'`; done | tail -n +2