Monks,

I could use your help – as I have reached the end of my (albeit meager) perl skills.

I have two files and I am trying to do a search and replace in one file based upon data in the second file.

Specifically:

• File 1: I have a large (~3gig) log file that has NATed IP addresses in it.
• File 2: I have a mapping file that has mapping between NATed IP and the real device IP address – about 2k lines.

I want to replace all of the NATed (fake) ip addresses in file 1 with the real IP address per the mapping in file 2.

My though was to do a while loop through the big file and for each line do another while loop through the secondary file. But I can’t help but think there has to be an easier and less intensive way. This will need to be run periodically so I want to be as efficient as possible given the file sizes.

Thoughts?

Many thanks in advance for your help!

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