This plugin is a front for ag, A.K.A. the_silver_searcher. Ag can be used as a replacement for 153% of the uses of ack. This plugin will allow you to run ag from vim, and shows the results in a split window.

You have to first install ag, itself. On Mac Homebrew, Gentoo Linux, several others, there's package named the_silver_searcher, but if your OS/distro don't have one, the GitHub repo installs fine:

git clone https://github.com/ggreer/the_silver_searcher ag && cd ag && ./build.sh && sudo make install

• Then, if you're using pathogen:

cd ~/.vim/bundle && git clone https://github.com/rking/ag.vim ag && vim  Helptags

• Or, if you're using Vundle:

echo "Plugin 'rking/ag.vim'" >> ~/.vimrc && vim  BundleInstall

You can specify a custom ag name and path in your .vimrc like so:

let g:agprg="<custom-ag-path-goes-here> --column"

:Ag [options] {pattern} [{directory}]

Search recursively in {directory} (which defaults to the current directory) for the {pattern}.

Files containing the search term will be listed in the split window, along with the line number of the occurrence, once for each occurrence. [Enter] on a line in this window will open the file, and place the cursor on the matching line.

Just like where you use :grep, :grepadd, :lgrep, and :lgrepadd, you can use :Ag, :AgAdd, :LAg, and :LAgAdd respectively. (See doc/ag.txt, or install and :h Ag for more information.)

Some characters have special meaning, and need to be escaped your search pattern. For instance, '#'. You have to escape it like this :Ag '\\\#define foo' to search for #define foo. (From blueyed in issue #5.)

Sometimes git grep is even faster, though in my experience it's not noticeably so.

In the quickfix window, you can use:

e    to open file and close the quickfix window
o    to open (same as enter)
go   to preview file (open but maintain focus on ag.vim results)
t    to open in new tab
T    to open in new tab silently
h    to open in horizontal split
H    to open in horizontal split silently
v    to open in vertical split
gv   to open in vertical split silently
q    to close the quickfix window

This Vim plugin is derived (and by derived, I mean copied, almost entirely) from milesz's ack.vim, which I also recommend installing since you might be in a situation where you have ack but not ag, and don't want to stop to install ag. Also, ack supports --type, and a few other features.