Shutdown only when no smb connection is open

shutdown.sh

#!/usr/bin/env bash

set -o xtrace   # output every line which gets executed
set -o nounset  # fail if an unset variable is used
#set -o errexit  # fail if a command exits with non-zero
set -o pipefail # fail if a command in a pipe fails

COUNTER=0

while test $COUNTER -le 30
do
	sleep 60

	SMB_CONNS=$(pgrep --full --count "smbd: client")

	if test $SMB_CONNS -gt 0
	then
		echo "$SMB_CONNS connections open"
		COUNTER=0
		continue
	fi

	COUNTER=$(( $COUNTER + 1 ))
done

echo "poweroff"
sudo poweroff