Language: Visual Basic .NET
Platform: Win9x, WinNT, Win2000/XP
This is a quick program I made to remove log entries from this site's AXS logs, but it should also work with most other log formats. It's meant to remove a line from a text file if it matches the regular expression provided. You give it an input file and output file, and it'll complete the search and copy in a relatively short time (50mb in ~5 secs). It also can just check to see if there are any matches without the copying. I used .NET because it has good built-in regex support and file IO performance.