Per-user repository statistic (commits, additions and deletions counter)

repostat

#!/usr/bin/env bash

set -e

BRANCH="$1"
IFS="|"

# Show help.
if [ "help" == "$BRANCH" ]; then
    echo "$0 BRANCH"
    exit 0
fi

: "${BRANCH:="master"}"
# Ensure that we're inside of directory with initialized Git repository.
git status > /dev/null
# Check local branch existence.
git rev-parse --verify "$BRANCH" > /dev/null
echo "Statistics for \"$BRANCH\":"

for DATA in $(git shortlog -sn --no-merges "$BRANCH" | awk 'BEGIN {FS = "\t"}; {print $1 "+" $2 "|"}'); do
    DATA=$(echo "$DATA" | xargs)
    COMMITS="${DATA%+*}"
    USERNAME="${DATA#*+}"

    echo "------------------------------------------------------------------"
    echo "$USERNAME ($COMMITS commits)"

    git log --author="$USERNAME" --shortstat | awk '/^ [0-9]/ {f += $1; i += $4; d += $6} \
      END {printf("%d files changed, %d insertions(+), %d deletions(-)", f, i, d)}'

    echo ""
done