Warning: Using a password on the command line interface can be insecure.

[root@qttc ~]# /usr/local/mysql/bin/mysqldump  -uroot -proot db > bak.sql
Warning: Using a password on the command line interface can be insecure.

翻译过来是：在命令行界面上使用密码能够是不安全的。

这让人有点郁闷，5.5用的一直都很爽，到5.6竟然说命令行方式写密码不安全？那密码写哪呢？

在官网文档找到了原因，你们能够点击这里看看：http://dev.mysql.com/doc/refman/5.1/en/password-security-user.html

MySQL users should use the following guidelines to keep passwords secure.

When you run a client program to connect to the MySQL server, it is inadvisable to specify your password in a way that exposes it to discovery by other users. The methods you can use to specify your password when you run client programs are listed here, along with an assessment of the risks of each method. In short, the safest methods are to have the client program prompt for the password or to specify the password in a properly protected option file.

英文有点烂，但大概读懂意思，翻译过来大意是在命令行下若是要使用密码能够在执行命令后的提示输入里输入密码，或者在指定的安全文件内指定密码。那安全文件时哪一个呢？文档对此给出了答案：

 Store your password in an option file. For example, on Unix, you can list your password in the [client] section of the .my.cnf file in your home directory:

能够在my.cnf内指定，因而打开个人my.cnf，在[mysqldump]下增长：

1 2	user=root password=root

文中说的在[client]下面加也能够，但那样就全部块的操做都能共享了，因此生产环境上为了安全仍是尽可能分开。保存退出再dump就ok了。

[root@qttc ~]# /usr/local/mysql/bin/mysqldump db > bak.sql[root@qttc ~]#