Detect newly added vars in .env.example and automatically merge them into .env

post-merge

#!/bin/bash

addedVars=$(git diff ORIG_HEAD HEAD --exit-code -- .env.example | tail -n +6 | grep '^\+' | sed '/^\+/ s/^\+//' | sed '/^[[:space:]]*$/d')
new=$(echo "$addedVars" | while read v; do
    if [[ !$(cat .env | grep ^$v=) ]]; then
    	echo $v
    fi
done)

if [[ "$new" ]]; then
	printf "New environment variables detected:\n"
	printf "$new"
	printf "\n"

	exec < /dev/tty
	read -p "Merge to .env? (y/n) " -r
	if [[ $REPLY =~ ^[Yy]$ ]]; then
		echo "$new" >> .env
	fi
fi

This script is meant to be added as post-merge hook under .git/hooks/post-merge in repositories. It will then be executed after every merge, including a git pull.

If the merge includes additions to .env.example and those additions represent variables that also do not exist in your local (gitignored) .env, it will offer to merge (add) those for you into this file.

It will NOT change variable values in your .env, nor will it ever delete variables.