Often, when converting files with search-and-replace or when collecting data, the original search match isn’t quite in the format you’d like it to be. E.g. when extracting Google queries from referring URLs in your web server’s log files, varies characters in the Google queries are URL-encoded, making them hard to read.
PowerGREP’s “extra processing” feature gives you the unique ability to search-and-replace each individual search match or substitution text with an extra regular expression or even an extra list of regular expressions. This way you can use far simpler regular expressions or even literal text to convert or extract the data in the format you want.
In the screen shot, you can see a PowerGREP action and its results, extracting Google queries from the logs of this web site. The action is available as an example in the PowerGREP library. The extra processing, which you can see in the bottom center of the screen shot, is set to a list of seven easy plain text substitutions. These replace the 7 most common URL-encoded characters in each collected Google query. Doing this with a single regular expression in a basic Windows grep tool would have been impossible.