一、簡介
Ag是用C++寫的，搜索速度快，比grep更有效率.
二、安裝
# ubuntu/debian
sudo apt-get install silversearcher-ag
# centos
sudo yum install the_silver_searcher
# mac
brew install the_silver_searcher
ag "鎖"
RHEL7+
rpm -Uvh http://download.fedoraproject.org/pub/epel/7/x86_64/e/epel-release-7-5.noarch.rpm
yum install the_silver_searcher
RHEL7－
wget ftp://ftp.pbone.net/mirror/ftp5.gwdg.de/pub/opensuse/repositories/utilities/CentOS_6/x86_64/the_silver_searcher-0.14-1.1.x86_64.rpm
rpm -ivh the_silver_searcher-0.14-1.1.x86_64.rpm