安装mac版的mysql后，
启动mysql 报错：
ERROR 2002 (HY000): Can’t connect to local MySQL server through socket ‘/var/lib/mysql/mysql.sock’ (2)
google了一下发现很多人遇到，解决方法都各不相同，于是去查了下安装包中的readme，里面说的很清楚了：
After the installation, you can start up MySQL by running the following
commands in a terminal window. You must have administrator privileges
to perform this task.
If you have installed the Startup Item, use this command:
shell> sudo /Library/StartupItems/MySQLCOM/MySQLCOM start
(ENTER YOUR PASSWORD, IF NECESSARY)
(PRESS CONTROL-D OR ENTER “EXIT” TO EXIT THE SHELL)
If you don’t use the Startup Item, enter the following command sequence:
shell> cd /usr/local/mysql
shell> sudo ./bin/mysqld_safe
(ENTER YOUR PASSWORD, IF NECESSARY)
(PRESS CONTROL-Z)
shell> bg
(PRESS CONTROL-D OR ENTER “EXIT” TO EXIT THE SHELL)
You should be able to connect to the MySQL server, for example, by
running `/usr/local/mysql/bin/mysql’.
完成上面的命令后，启动mysql成功