get-stale-branches.sh

#!/bin/bash

compare='dev'
min_commits_ahead=5
max_commits_behind=500
max_time_elapsed="$((30 * 24 * 60 * 60))"

git fetch origin 2> /dev/null
branches="$(\
    git remote show origin \
    | awk '/Remote branches/ {f = 1; next} /Local branches/ {f = 0} f' \
    | awk '{print ($1 ~ /refs/) ? $1 : "refs/remotes/origin/"$1}' \
    | grep -vE /refs\/remotes\/origin\/$compare/
)"

current_date="$(date '+%s')"

for branch in $branches; do
    counts="$(git rev-list --left-right --count $compare)"
    ahead="$(echo $counts | awk '$1')"
    behind="$(echo $counts | awk '$2')"

    last_commit_date="$(git show --format='%ct' $branch)"
    time_elapsed="$(($current_date - $last_commit_date))"

    #$ahead -lt $min_commits_ahead -a $behind -ge $max_commits_behind -o

    if [ $time_elapsed -gt $max_time_elapsed ]; then
        echo "$branch (-$behind, +$ahead)"
    fi
done