Write logs

I want to write several logs in the same connexion. The problem with logging framework is that only can filter a log;

For example, If i had three filters with log_metadata= T, i would like to write in three differents logs




function filter_conn(id: Log::ID, path: string, rec: Conn::Info) : string {

local filters = Filter::filters;
local file_filter = “”;

for (i in filters) {

if (i?$log_metadata && i$log_metadata == T) {

file_filter = “filter-” + cat(i$id_fil);

return file_filter;

event bro_init() {

local metadata: Log::Filter = [
$include=set(“ts”,“id.orig_h”, “id.orig_p”, “id.resp_h”, “id.resp_p”, “proto”, “service”,
“duration”, “orig_bytes”, “resp_bytes”, “missed_bytes”, “orig_pkts”, “resp_pkts”, “orig_file”,

Log::add_filter(Conn::LOG, metadata);


With this code, I only return the first match, filter-1.log

How could I do this?


The problem is that path_func is not for filtering, it is for splitting a single log stream into one or more different output files.
If you want to filter a log file, you need to use $pred, not $path_func.

You simply need to call Log::add_filter 3 times, once for each pred function.