Ack-grep tool for vim, put in .vimrc

gistfile1.txt

:GrepTab <search term> <path> will open a new tab and show you all results from ack-grep of the search term on the path given. No path will default to current directory  
(I recommend you ad `set autochdir` to your .vimrc as well, so that the "present working directory" is always at the file your editing. It makes searching for stuff easier)

   nnoremap <leader>f :GrepTab "example binding

   function! s:NewTabGrep(...)
       let args=split(a:1)
       if len(args) == 2
           let dir=args[1]
       else
           let dir='.'
       endif
       echom args[0] . "  " . shellescape(dir)
       tabnew | execute "r ! ack-grep ". shellescape(args[0]) ." ". shellescape(dir)
   endfunction
   com! -nargs=? GrepTab call s:NewTabGrep('<args>')