Apache HTTP Server Version 2.5
logresolve is a post-processing program to
resolve IP-addresses in Apache's access logfiles. To minimize
impact on your nameserver, logresolve has its very own internal
hash-table cache. This means that each IP number will only be
looked up the first time it is found in the log file.
Takes an Apache log file on standard input. The IP addresses must be the first thing on each line and must be separated from the remainder of the line by a space.