[syslog-ng]Destiniation program question

Aaron Jackson syslog-ng@lists.balabit.hu
Tue, 22 Jul 2003 11:29:56 -0400

I am trying to get syslog-ng 1.6.0rc3 to run a program as soon as it 
receives a  message that matches a specific string, but I am having a 
few problems.  My syslog-ng.conf file has the following set up:

options { sync (0);
          time_reopen (10);
          log_fifo_size (1000);
          long_hostnames (off);
          use_dns (yes);
          use_fqdn (no);
          create_dirs (yes);
          keep_hostname (yes);

source s_sys { sun-streams ("/dev/log" door("/etc/.syslog_door")); 
internal(); };
source s_udp { udp(); };
source s_tcp { tcp(); };
destination d_prog { program("/path/to/program.pl" 
template("$HOST,$MSG\n")); };
filter f_fetch { level(notice) and match("MATHC_STRING"); };
log {source(s_sys); source(s_udp); source(s_tcp); filter(f_fetch); 
destination(d_prog); };

My first question is an easy one.  My perl program has the form:

while ($line=<>) {

Is this correct?  When syslog-ng forks my perl script, can I assum that 
STDIN is always open or should my script have a form like so?

while (1) {

My second question has to do with when the perl script is run.  It looks 
like syslog-ng waits for either several log messages or gets a SIGTERM 
(or similar) before it runs the program.  I would like for this to 
happen in real time.  The only option I see that might change the timimg 
of when the program is run is log_fifo_size.  But since I have to use a 
production system that collects over 20K log messages/day for 
development (yes, this is bad), I would like to know if I'm on the right 
track before I change anything.  Any info would be helpful.  Thanks.