[syslog-ng] CSV parser and empty fields

[Bill Anderson]

I'm using a tab separated format from apache for access logs. My last two fields are referrer and user-agent. Obviously sometimes there is no referrer. Unfortunately when there isn't one apache only logs an empty string instead of the more common "-". This isn't a problem in scripts that parse the resulting logfile as they see the resulting empty field when I log $MSG. 

However, I just started a new log file that uses the csv-parser w/tab as delimiter and when the referrer field is empty, APACHE.USERAGENT (the last field) gets rolled into APACHE.REFERRER, the second to last field. As a result the template for this page (which uses APACHE.REFERRER) isn't reliable. When REFERRER is empty I want it to be empty (or something I can specify, like a default) not he next field in the parser definition.

I've look at the manual and don't see anything about handling empty fields. How do I get syslog-ng/csv-parser to log the empty field instead of moving to the next one?

Cheers,
Bill