HomeBrew

HOMEBREW (or Macports) is similar to the Yum and APT-GET tools under the Linux platform, which is an excellent package management tool. Here I chose Homebrew. (Why, because I only need one tool, it is enough o (∩_∩) o ~)

About Homebrew, poke herehttp://brew.sh/index_zh-cn.html

Installation script (Mac comes with Ruby, no need to install)

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

upgrade brew

brew update 

uninstall Brew
//

View the installed package

brew list

The Silver Searcher

The Silver Searcher is a tool for searching code. It started off as a clone of Ack, but their feature sets have since diverged slightly. In typical usage, Ag is 5-10x faster than Ack. See the GitHub page for more info.
is similar to ACK (Ruby), but it is implemented with C, so faster.
Click here to pokehttp://geoff.greer.fm/ag/

Install AG (The Silver Searcher)

brew install the_silver_searcher

Uninstall AG

brew uninstall the_silver_searcher

If there is permission problem, such as Cannot Write and the like:

sudo chown -R David /usr/local

When I installed AG, Error “/USR/LOCAL/BIN is Not Writable” appeared

sudo chown -R David /usr/local/bin
sudo chown -R David /usr/local/share

When Brew Install the_silver_Searcher Warning: The_silver_searcher-0.31.0 Already Installed, it ’s just not linked
Yes:

brew link the_silver_searcher

Update at 2016.04.08
The bash used by my Mac is ZSH,
When using AG, report an error:
zsh:command not found:ag
Solution:

cd ~
ls -a
vim .zshrc

.zshrc is a configuration file of ZSH Shell.
I added my homebrew/bin path at Line58 Path
/usr/local/homebrew/bin
Restart Terminal and it is OK.