churn number and file name
git log --all -M -C --name-only | grep -E '^(app|lib)/' | sort | uniq -c | sort | awk 'BEGIN {print "count,file"} {print $1 "," $2}'


graph of churn number and frequency
git log --all -M -C --name-only | grep -E '^(app|lib)/' | sort | uniq -c | sort | awk '{print $1}' | uniq -c | sort | awk 'BEGIN { print "frequency,churn_count"} { print $1,$2}'