ack.vim is a Vim plugin interface to the ack command-line tool, providing fast, grep-like search functionality directly within Vim. It displays search results in a split window and supports navigation through them seamlessly. This plugin was designed as a Vim frontend for the programmer's search tool ack. ack can be used as a replacement for 99% of the uses of grep. The plugin allows you to search with ack from within Vim and shows the results in a split window. But here's a little secret...
the script do the following: taking passed arguments - pattern for matching pathnames - path – directory to search for pattern - format to return the search results search all dirs and subdirs in the working dir (path) return search results.