• “静态”主机名也称为“内核主机名”，是系统在启动时自动从“/etc/hostname”文件初始化的主机名。
• “瞬态”主机名是在系统运行时临时分配的主机名。如由“DHCP”或“mDNS”服务器分配。
• “灵活”主机名允许使用特殊字符(包括空格）的主机名，而其他两种都必须遵从“互联网域名”字符限制规则。

hostnamectl status --static #查看静态主机名

hostnamectl status --transient #查看瞬态主机

hostnamectl status --pretty #查看灵活主机名

hostnamectl set-hostname %Aiezu.com%

#查看修改后的状态：

hostnamectl status --static 

#aiezu.com

hostnamectl status --transient 

#aiezu.com

hostnamectl status --pretty 

#%Aiezu.com%

#修改静态主机名

hostnamectl set-hostname --static aiezu.com



#修改瞬态主机

hostnamectl set-hostname --transient aiezu.com



#修改灵活主机名

hostnamectl set-hostname --pretty aiezu.com

127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4

::1         localhost localhost.localdomain localhost6 localhost6.localdomain6

127.0.0.1   aiezu.com localhost localhost.localdomain localhost4 localhost4.localdomain4

::1         aiezu.com localhost localhost.localdomain localhost6 localhost6.localdomain6

[root@localhost ~]# hostnamectl set-hostname aiezu.com

[root@localhost ~]# su -

上一次登录：三 11月  2 02:17:43 CST 2016从 10.0.0.52pts/0 上

[root@aiezu ~]#

[root@aiezu ~]# hostname

aiezu.com

[root@aiezu ~]# cat /etc/hostname 

aiezu.com

hostnamectl set-hostname aiezu.com

# su -

• 操作系统：CentOS 7.0 64位（最小安装）
• MariaDB版本：系统自带（mariadb-5.5.50-1.el7_2）

#检查是否安装mysql

rpm -qa|grep mysql-server

#如果已经安装，则卸载（爱E族aiezu.com）

yum remove mysql

yum remove mysql-server

#检查是否安装mariadb

rpm -qa|grep mariadb

#如果已经安装，则卸载

yum remove mariadb-server

yum remove mariadb

lsof -i :3306

yum -y update

yum -y install mariadb mariadb-server

//启动服务

service mariadb start

//查看运行状态（爱E族）

service mariadb status

//设置密码：输入下面命令，回车后输入两次新密码

mysqladmin password

//修改密码：输入下面命令，回车后输入旧密码，再回车输入两次新密码

mysqladmin -p password

/usr/bin/mysql_secure_installation:行379: find_mysql_client: 未找到命令



NOTE: RUNNING ALL PARTS OF THIS SCRIPT IS RECOMMENDED FOR ALL MariaDB

      SERVERS IN PRODUCTION USE!  PLEASE READ EACH STEP CAREFULLY!



In order to log into MariaDB to secure it, we'll need the current

password for the root user.  If you've just installed MariaDB, and

you haven't set the root password yet, the password will be blank,

so you should just press enter here(aiezu.com).



Enter current password for root (enter for none): 

OK, successfully used password, moving on...



Setting the root password ensures that nobody can log into the MariaDB

root user without the proper authorisation.



You already have a root password set, so you can safely answer 'n'.



Change the root password? [Y/n] n

 ... skipping.



By default, a MariaDB installation has an anonymous user, allowing anyone

to log into MariaDB without having to have a user account created for

them.  This is intended only for testing, (http://aiezu.com)and to make the installation

go a bit smoother.  You should remove them before moving into a

production environment.



Remove anonymous users? [Y/n] y

 ... Success!



Normally, root should only be allowed to connect from 'localhost'.  This

ensures that someone cannot guess at the root password from the network.



Disallow root login remotely? [Y/n] y

 ... Success!



By default, MariaDB comes with a database named 'test' that anyone can

access.  This is also intended only for testing, and should be removed

before moving into a production environment.



Remove test database and access to it? [Y/n] y

 - Dropping test database...

ERROR 1008 (HY000) at line 1: Can't drop database 'test'; database doesn't exist

 ... Failed!  Not critical, keep moving...

 - Removing privileges on test database...

 ... Success!



Reloading the privilege tables will ensure that all changes made so far

will take effect immediately.



Reload privilege tables now? [Y/n] y

 ... Success!



Cleaning up...



All done!  If you've completed all of the above steps, your MariaDB

installation should now be secure.



Thanks for using MariaDB!

//运行下面命令，并输入刚才修改的密码

mysql -uroot -p

--创建一个只允许本机登录的帐号“aiezu”(爱E族),其中“your_password”为帐号的密码；

--如果创建允许远程登录的帐号，请将“localhost”改成“%”

CREATE USER 'aiezu'@'localhost' IDENTIFIED BY 'your_password';

--CREATE USER 'aiezu'@'%' IDENTIFIED BY 'your_password';

create database aiezu_db default character set 'utf8';

--授权给aiezu(aiezu.com)

grant all privileges on aiezu_db.* to 'aiezu'@'localhost';

--刷新权限

flush privileges;

//输入下面一条命令回车后输入创建用时使用的密码，这里上面使用的是“your_password”

mysql -u aiezu -p

//登录后use aiezu_db

systemctl restart firewalld

firewall-cmd --zone=public --add-port=3306/tcp --permanent

firewall-cmd --reload

• 接口通过“interface”关键词来定义；
• 上下级接口可以通过“extends”关键词继承；
• 接口所有方法都是“public”权限（爱E族）；
• 接口可以定义常量成员，但不能定义变量成员；
• 类通过“implements”关键词来实现接口，类必须完全实现接口定义的所有功能；
• 一个类可以同时“implements”（实现）一个到多个接口；

//定义一个文章接口

interface Article {

    //接口中有一个发布文章的接口

    public function publishArticle();

}

interface Ask {

    public function question();

    public function answer();

}

//定义Article2接口，继承Article接口

interface Article2 extends Article {

    //Article2接口比Article多了一个转发文章功能（爱E族）

    public function relayArticle();

}

//Aiezu（爱E族）类要实现Article（文章）和问答（Ask）接口功能

class Aiezu implements Article,Ask {

    public function publishArticle() {

        echo "发布了一篇文章\n";

    }

    public function relayArticle() {

        echo "转发了一篇文章\n";

    }

    public function question() {

        echo "发表了一个问题\n";

    }

    public function answer(){

        echo "回答一个问题\n";

    }

}

$aiezu = new Aiezu();

$aiezu->relayArticle();

$aiezu->question();

PHP Fatal error:  Class Aiezu contains 1 abstract method and must therefore be declared abstract or implement the remaining methods (Article::publishArticle) in /tmp/xxx.php on line xxx

//对Date的扩展，将 Date 转化为指定格式的字符串

//年(y)、月(m)、日(d)、星期(w)、小时(h)、分(i)、秒(s)、毫秒(u)

//用法：new Date().format("yyyy-mm-dd hh:ii:ss.u") ==> 2016-10-28 23:17:49.085

Date.prototype.format = function( format ) {

    if ( typeof format !== "string" ) format = 'yyyy-mm-dd hh:ii:ss';

    function fillZore(num, len) {

        while(num.toString().length<len){

            num = '0'+num;

        }

        return num;

    }

 

    var Week = ['日','一','二','三','四','五','六']; 

   

    format=format.replace(/yyyy|YYYY/,this.getFullYear());  

    format=format.replace(/yy|YY/, fillZore(this.getYear() % 100, 2)); 

    format=format.replace(/mm|MM/, fillZore(this.getMonth()+1, 2));

    format=format.replace(/m|M/g, this.getMonth()+1);  

    format=format.replace(/dd|DD/, fillZore(this.getDate(), 2));  

    format=format.replace(/d|D/g,this.getDate());  

     

    format=format.replace(/w|W/g, Week[this.getDay()]);  

   

    format=format.replace(/hh|HH/, fillZore(this.getHours(), 2));  

    format=format.replace(/h|H/g, this.getHours());  

    format=format.replace(/ii|II/, fillZore(this.getMinutes(), 2));  

    format=format.replace(/i|I/g, this.getMinutes());  

    format=format.replace(/ss|SS/, fillZore(this.getSeconds(), 2));  

    format=format.replace(/s|S/g, this.getSeconds()); 



    format=format.replace(/u|U/g, fillZore(this.getMilliseconds(), 3)); 

    return format;  

}

//2016-10-28 23:17:49.085

new Date().format("yyyy-mm-dd hh:ii:ss.u")

//2011年01月02日10时22分33秒

new Date("2011/01/02 10:22:33").format("yyyy年mm月dd日hh时ii分ss秒");

//2016-10-28

new Date().format("yyyy-mm-dd");

//22:53

new Date().format("hh:ii");

#lat为纬度, lng为经度, 一定不要弄错

declare @lng1 float;

declare @lat1 float;

declare @lng2 float;

declare @lat2 float;

set @lng1=116.3899;

set @lat1=39.91578;

set @lng2=116.3904;

set @lat2=39.91576;  

select (2*ATAN2(SQRT(SIN((@lat1-@lat2)*PI()/180/2)   

        *SIN((@lat1-@lat2)*PI()/180/2)+   

        COS(@lat2*PI()/180)*COS(@lat1*PI()/180)   

        *SIN((@lng1-@lng2)*PI()/180/2)   

        *SIN((@lng1-@lng2)*PI()/180/2)),   

        SQRT(1-SIN((@lat1-@lat2)*PI()/180/2)   

        *SIN((@lat1-@lat2)*PI()/180/2)   

        +COS(@lat2*PI()/180)*COS(@lat1*PI()/180)   

        *SIN((@lng1-@lng2)*PI()/180/2)   

        *SIN((@lng1-@lng2)*PI()/180/2))))*6378140;

#返回结果： 42.7484246368099

# use aiezu;

drop function getDistance;

DELIMITER $$  

CREATE DEFINER=`root`@`localhost` FUNCTION `getDistance`(

     lng1 float(10,7) 

    ,lat1 float(10,7)

    ,lng2 float(10,7) 

    ,lat2 float(10,7)

) RETURNS double

begin

    declare d double;

    declare radius int;

    set radius = 6378140; #假设地球为正球形，直径为6378140米

    set d = (2*ATAN2(SQRT(SIN((lat1-lat2)*PI()/180/2)   

        *SIN((lat1-lat2)*PI()/180/2)+   

        COS(lat2*PI()/180)*COS(lat1*PI()/180)   

        *SIN((lng1-lng2)*PI()/180/2)   

        *SIN((lng1-lng2)*PI()/180/2)),   

        SQRT(1-SIN((lat1-lat2)*PI()/180/2)   

        *SIN((lat1-lat2)*PI()/180/2)   

        +COS(lat2*PI()/180)*COS(lat1*PI()/180)   

        *SIN((lng1-lng2)*PI()/180/2)   

        *SIN((lng1-lng2)*PI()/180/2))))*radius;

    return d;

end

$$

DELIMITER ; 

select getDistance(116.3899,39.91578,116.3904,39.91576); #调用函数

#返回结果：43.045058294389

This function has none of DETERMINISTIC, NO SQL, or READS SQL DATA in its declaration and binary logging is enabled (you *might* want to use the less safe log_bin_trust_function_creators variable)

set global log_bin_trust_function_creators=1;

log_bin_trust_function_creators=1

#lng为经度，lat为纬度，一定不要弄错了哦

function distance($lat1, $lng1, $lat2, $lng2){

    return (2*ATAN2(SQRT(SIN(($lat1-$lat2)*PI()/180/2)

    *SIN(($lat1-$lat2)*PI()/180/2)+

    COS($lat2*PI()/180)*COS($lat1*PI()/180)

    *SIN(($lng1-$lng2)*PI()/180/2)

    *SIN(($lng1-$lng2)*PI()/180/2)),

    SQRT(1-SIN(($lat1-$lat2)*PI()/180/2)

    *SIN(($lat1-$lat2)*PI()/180/2)

    +COS($lat2*PI()/180)*COS($lat1*PI()/180)

    *SIN(($lng1-$lng2)*PI()/180/2)

    *SIN(($lng1-$lng2)*PI()/180/2))))*6378140;

}

echo distance(39.91917,116.3896,39.91726,116.3940);

// 输出结果：431.65898565454

function getDisance(lat1, lng1, lat2, lng2) { // lat为纬度, lng为经度, 一定不要弄错

    function toRad(d) {  return d * Math.PI / 180; }

    var dis = 0;

    var radLat1 = toRad(lat1);

    var radLat2 = toRad(lat2);

    var deltaLat = radLat1 - radLat2;

    var deltaLng = toRad(lng1) - toRad(lng2);

    var dis = 2 * Math.asin(Math.sqrt(Math.pow(Math.sin(deltaLat / 2), 2) + Math.cos(radLat1) * Math.cos(radLat2) * Math.pow(Math.sin(deltaLng / 2), 2)));

    return dis * 6378137;

} 

alert(  getDisance(39.91917,116.3896,39.91726,116.3940) );

// 弹出：431.65878299633806(米)

ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)

• 将连接参数“host”的值由“localhost”改成“127.0.0.1”；
• 按下面方法，在“/etc/mysql.cnf”中指定“sock文件”位置。

一、查看mysql服务的socket文件位置：

[mysqld]

datadir=/storage/aiezu.com/mysql

socket=/storage/aiezu.com/mysql/mysql.sock

user=mysql

二、修改my.cnf文件解决问题：

[mysqld]

datadir=/storage/aiezu.com/mysql

socket=/storage/aiezu.com/mysql/mysql.sock

 

[mysql]

socket=/storage/aiezu.com/mysql/mysql.sock



[client]

socket=/storage/aiezu.com/mysql/mysql.sock



[mysqldump]

socket=/storage/aiezu.com/mysql/mysql.sock

 

[mysqladmin]

socket=/storage/aiezu.com/mysql/mysql.sock

三、php连接mysql服务提示"Can't connect to local MySQL server through socket..."的解决方法：

[MySQL]

...省略n行...

mysql.default_socket = "/storage/aiezu.com/mysql/mysql.sock"

四、python连接mysql提示"Can't connect to local MySQL server through socket..."的解决方法：

#!/usr/bin/python

from MySQLdb import connect

conn = connect(db="pzy", user="root", host="localhost", unix_socket="/storage/aiezu.com/mysql/mysql.sock")

cur = conn.cursor()

count=cur.execute("show databases")

print 'there has %s dbs' % count

conn.commit()

conn.close()

五、 php pdo连接mysql提示"Can't connect to local MySQL server through socket..."的解决方法:

<?php

$dsn = "mysql:host=localhost;dbname=pzy;unix_socket=/storage/aiezu.com/mysql/mysql.sock";

$db = new PDO($dsn, 'root', '');

$rs = $db->query("SELECT * FROM qrtest");

while($row = $rs->fetch()){

    print_r($row);

}

?>

• ERROR 2002 (HY000): Can't connect to local MySQL server through socket '***' (2)

<?php

//删除所有ascii字符

echo preg_replace("#[\x{00}-\x{ff}]#u", "", "abc!@爱E族#{}x aiezu.com");

//输出: 爱族



//删除所有非ascii字符

echo preg_replace("#[^[:ascii:]]#u", "", "abc!@爱E族#{}x aiezu.com");

//输出: abc!@E#{}x aiezu.com