[root@testmysql bin]# ./mysql
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)

解决方法：

由于mysql 默认的mysql.sock 是在/usr/local/mysql/data/mysql.sock，但linux系统总是去/tmp/mysql.sock查找，所以会报错

1.直接指定mysql通道

据我知道的（ps：我是菜鸟，请纠正），老版本(5.4之前)的是：/var/lib/mysql/mysql.sock

 在新版本中默认是在/usr/local/mysql/data/mysql.sock，具体的可以去查看my.cnf文件里面

[root@testmysql bin]# ./mysql --socket=/usr/local/mysql/data/mysql.sock
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.6.4-m7 Source distribution
Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql>

2. 创建符号连接：

为mysql.sock增加软连接（相当于windows中的快捷方式）。

ln -s /var/lib/mysql/mysql.sock /tmp/mysql.sock

eg：
root@localhost ~]# mysql
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)
[root@testmysql bin]# ln -s /var/lib/mysql/mysql.sock /tmp/mysql.sock

插曲：有可能你在建立连接的时候出现下面的情况，
[root@testmysql bin]# ln -vs /usr/local/mysql/data/mysql.sock /tmp/mysql.sock
ln: creating symbolic link `/tmp/mysql.sock': File exists
没关系，加上-f参数就可以了。-f的主要过程：先将同名的软链接dd删除，然后再创建硬链接dd

[root@testmysql bin]# ln -f /usr/local/mysql/data/mysql.sock /tmp/mysql.sock
[root@testmysql bin]# ./mysql
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.6.4-m7 Source distribution
Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql>