#!/bin/bash [[ $XT_MULTI == *xtables-nft-multi ]] || { echo "skip $XT_MULTI"; exit 0; } nft -v >/dev/null || { echo "skip $XT_MULTI (no nft)"; exit 0; } coproc $XT_MULTI iptables-restore --noflush cat >&"${COPROC[1]}" <&"${COPROC[1]}" sleep 1 [[ -n $COPROC_PID ]] && kill $COPROC_PID wait