wg-resolv

#!/usr/bin/env bash

set -e
set -u
set -o pipefail

[ -z "${WG_COLOR_MODE:-}" ] && export WG_COLOR_MODE=always

while IFS= read -r line; do
	if [[ "${line}" == *"allowed ips"* ]]; then
		echo "${line}" | cut -d' ' -f1-4 | tr -d $'\n'
		echo -n ' '

		first=1
		for ip in $(echo "${line}" | cut -d' ' -f5-); do
			if [ "${first}" = 1 ]; then
				first=0
			else
				echo -n ", "
			fi
			ip="${ip%,}"

			cidr="$(echo "${ip}" | cut -d'/' -f2 | sed -r "s/\x1B\[([0-9]{1,2}(;[0-9]{1,2})?)?[mGK]//g")"
			ip="$(echo "${ip}" | cut -d'/' -f1 | sed -r "s/\x1B\[([0-9]{1,2}(;[0-9]{1,2})?)?[mGK]//g")"
			if [[ "${ip}" == *":"* && "${cidr}" == 128 ]] || [[ "${ip}" != *":"* && "${cidr}" == 32 ]]; then
				set +e
				hostsEntry="$(getent hosts "${ip}")"
				ret="$?"
				set -e
				if [ "${ret}" != 0 ]; then
					echo -n "${ip}/${cidr}"
				else
					echo "${hostsEntry}" | awk '{print $2}' | tr -d '\n'
				fi
			else
				echo -n "${ip}/${cidr}"
			fi
		done
		echo
	else
		echo "${line}"
	fi
done < <(wg "${@}")