check-env-dep

#!/usr/bin/env sh

generate_random_string() {
	# While this command might not produce 6 pseudo random lower case letters, depending on the content of `/dev/urandom`, it should
	# do so most of the time. Even if the output is a shorter string, this should not matter for the purpose of this script.
	head /dev/urandom | LC_ALL=C tr -dc 'a-z' | head -c 6
}

if [ -z "$KDB" ]; then
	KDB=kdb
fi
KDB="$(which "$KDB")"

ORIG_PATHS="$("$KDB" mount-list-all-files)"
ENV="$(env 2> /dev/null)"

if [ -z "$ENV" ]; then
	echo "no environment variables found"
	exit 1
fi

printf '%s\n' "$ENV" | while IFS='' read -r env; do
	# The script does **not** handle environment variables that contain newlines properly!
	printf '%s' "$env" | grep -Eq '^[_a-zA-Z][_a-zA-Z]*=.*' || continue
	NAME="$(echo "$env" | cut -d '=' -f1 2> /dev/null)"
	if [ "$NAME" = "KDB" ] || [ "$NAME" = "PATH" ]; then
		continue
	fi
	ORIG_VALUE="$(echo "$env" | cut -d '=' -f2- 2> /dev/null)"
	NEW_VALUE=$(generate_random_string)
	export "$NAME"="$NEW_VALUE" > /dev/null 2>&1
	NEW_PATHS="$("$KDB" mount-list-all-files 2> /dev/null)"
	ORIG_PATHS_FILE="$(mktemp)"
	NEW_PATHS_FILE="$(mktemp)"
	echo "$ORIG_PATHS" | sort 2> /dev/null > "$ORIG_PATHS_FILE"
	echo "$NEW_PATHS" | sort 2> /dev/null > "$NEW_PATHS_FILE"
	DIFF="$(comm -3 "$ORIG_PATHS_FILE" "$NEW_PATHS_FILE")"
	rm "$ORIG_PATHS_FILE" "$NEW_PATHS_FILE"
	if [ ! -z "$DIFF" ]; then
		echo "$NAME influences $DIFF"
	fi
	export "$NAME"="\"$ORIG_VALUE\"" > /dev/null 2>&1
done