mac os x 把reids nignx mongodb做成随机启动吧

~/Library/LaunchAgents 由用户自己定义的任务项
/Library/LaunchAgents 由管理员为用户定义的任务项
/Library/LaunchDaemons 由管理员定义的守护进程任务项
/System/Library/LaunchAgents 由Mac OS X为用户定义的任务项
/System/Library/LaunchDaemons 由Mac OS X定义的守护进程任务项

大部分安装完都会有一个plist，下面以nginx为例：

1.把plist拷到/Library/LaunchDaemons

sudo cp /usr/local/opt/nginx/*.plist /Library/LaunchDaemons

2.【可选】修改plist参数或增加其他（增加日志文件存放位置等） 

3.修改权限

sudo chown root:wheel /Library/LaunchDaemons/homebrew.mxcl.nginx.plist

4.启动

sudo launchctl load /Library/LaunchDaemons/homebrew.mxcl.nginx.plist

sudo launchctl start homebrew.mxcl.nginx

参考：

http://stepquick.net/blog/2014/04/28/start-nginx-at-launch-on-mavericks/

https://alicoding.com/how-to-start-mongodb-automatically-when-starting-your-mac-os-x/