之前在使用LNMP一键安装包（其中的有些默认配置还是不够安全的，比如php.ini中的一些设置）的时候看到了其中的MySQL设置密码功能的脚本片断，觉得很有用，就摘录如下：

#!/bin/bash
PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bin
export PATH

# Check if user is root
if [ $(id -u) != "0" ]; then
    echo "Error: You must be root to run this script, please use root to install lnmp"
    exit 1
fi

#set mysql root password

	mysqlrootpwd="root"
	echo "Please input the root password of mysql:"
	read -p "(Default password: root):" mysqlrootpwd
	if [ "$mysqlrootpwd" = "" ]; then
		mysqlrootpwd="root"
	fi
	echo "==========================="
	echo "mysqlrootpwd=$mysqlrootpwd"
	echo "==========================="

/etc/init.d/mysql start
/usr/local/mysql/bin/mysqladmin -u root password $mysqlrootpwd

cat > /tmp/mysql_sec_script<<EOF
use mysql;
update user set password=password('$mysqlrootpwd') where user='root';
delete from user where not (user='root') ;
delete from user where user='root' and password='';
drop database test;
DROP USER ''@'%';
flush privileges;
EOF

/usr/local/mysql/bin/mysql -u root -p$mysqlrootpwd -h localhost < /tmp/mysql_sec_script

其中的一些代码片段其实都可以独自摘录下来单独使用。