logstash filter string split with control unicode character(\001, start of heading), or regexp

logstash_split_regexp.conf

filter{
    ruby {
        code => "event.set('message', event.get('message').split(/\001\s+/, -1)); event.set('@timestamp', LogStash::Timestamp.now)"
        add_field => {
            "time" => "%{[message][0]}"
            "level" => "%{[message][1]}"
            "thread" => "%{[message][2]}"
            "msg" => "%{[message][3]}"
            "location" => "%{[message][4]}"
            "stacktrace" => "%{[message][5]}"
        }
        remove_field => ["message"]
    }
}

# split second param -1 for empty string
# this might be grok filter usage, but just split and no PATTERN use
# event.set('@timestamp', LogStash::Timestamp.now) for replace filebeat @timestamp with logstash processed time