Script to find mentions of git commit hashes in commit messages or diffs

hashes.sh

(
    commits=($(git log --pretty='format:%h' -S'\b[a-f0-9]{7,}\b' --pickaxe-{all,regex}));
    commits+=($(git log --pretty='format:%h' --grep='\b[a-f0-9]\{7,\}\b'));
    for commit in ${commits[*]}; do
        for shaish in $(git show $commit | tail -n+5 | grep -v '^index' | grep -oe '[a-f0-9]\{7,\}'); do
            if git rev-list HEAD.."$shaish" &> /dev/null; then
                echo $shaish;
            fi
        done
    done
) | sort | uniq