dirs-changed-since-last-commit

#!/usr/bin/env bash
# 
# Sample script which outputs the list of root level directories containing
# modified files in the last commit
# 
set -euo pipefail
IFS=$'\n\t'

changedDirs=()

find_in_array() {
    local word array
    word="${1:-}"
    array="${2-}"
    for e in "${array[@]}"; do [[ "$e" == "$word" ]] && return 0 || return 1; done
}

while read -r file ; do
    baseDir="${file%%/*}"
    find_in_array "$baseDir" "${changedDirs[@]}" || changedDirs+=("$baseDir")

done < <(git diff-tree --no-commit-id --name-only -r HEAD^)

echo "Changed Dirs = ${changedDirs[*]}"