Remove duplicates in text file

I'm using NXLog to read a log file and send it to Logstash.  This works fine, but some of the log lines are duplicates.  They're in separate lines, but the content is exactly the same.  I can't change the way the logs are written to the log file, so the only way is to fix it either with NXLog before it gets send, or in Logstash when it arrives, which I prefer not to do.

I see NXLog does have a function for this, but it's not working for me.  I've tried this in my config file.

AskedJuly 27, 2015 - 2:38pm