PHP GUID generation function and class _php instance

Introduction of the GUID
GUID: The globally unique Identifier (globally unique identifier) is also known as the UUID (universally unique Identifier). A GUID is a binary length 128-bit numeric identifier generated by a specific algorithm that indicates the uniqueness of the product. GUIDs are primarily used to assign identifiers that must be unique in a network or system that has more than one node or multiple computers.
On Windows platforms, GUIDs are widely used in Microsoft's products to identify objects such as registry entries, class and interface identities, databases, system directories, and so on.
The GUID is formatted as "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx", where each x is a 32-bit hexadecimal number in the range 0-9 or a-f. For example: 6F9619FF-8B86-D011-B42D-00C04FC964FF is a valid GUID value.
Second, the advantages of the GUID
1.GUID is unique in space and time, ensuring that different numbers are produced at the same time and in different places.
2. No two computers in the world generate duplicate GUID values.
3. When the GUID is required, it can be automatically generated by the algorithm, without the need of an authoritative agency to manage it.
The 4.GUID is fixed in length and relatively short, and is ideal for sorting, labeling, and storage.
Third, GUID generation function

Copy Code code as follows:

function Create_guid () {
$charid = Strtoupper (MD5 (Uniqid (Mt_rand (), true));
$hyphen = Chr (45);//"-"
$uuid = Chr (123)//"{"
. substr ($charid, 0, 8). $hyphen
. substr ($charid, 8, 4). $hyphen
. substr ($charid, 4). $hyphen
. substr ($charid, 4). $hyphen
. substr ($charid, 20,12)
. chr (125);//"}"
return $uuid;
}

third, GUID generation class
PHP Get GUID class: guid_class.php

Copy Code code as follows:

<?php
Class System
{
function Currenttimemillis ()
{
List ($usec, $sec) = Explode ("", Microtime ());
Return $sec. substr ($usec, 2, 3);
}
}
Class Netaddress
{
var $Name = ' localhost ';
var $IP = ' 127.0.0.1 ';
function Getlocalhost ()//static
{
$address = new Netaddress ();
$address->name = $_env["COMPUTERNAME"];
$address->ip = $_server["Server_addr"];
return $address;
}
function toString ()
{
Return Strtolower ($this->name. ' /'. $this->ip);
}
}
Class Random
{
function Nextlong ()
{
$tmp = rand (0,1)? ' -':'';
Return $tmp. Rand (1000, 9999). RAND (1000, 9999). RAND (1000, 9999). Rand (+ 999). RAND (100, 999);
}
}
Three paragraphs
A paragraph is a microsecond, an address, a random number.
Class Guid
{
var $valueBeforeMD 5;
var $valueAfterMD 5;
function Guid ()
{
$this->getguid ();
}
//
function GetGuid ()
{
$address = Netaddress::getlocalhost ();
$this->valuebeforemd5 = $address->tostring (). ': '. System::currenttimemillis (). ': '. Random::nextlong ();
$this-&GT;VALUEAFTERMD5 = MD5 ($this->valuebeforemd5);
}
function NewGuid ()
{
$Guid = new Guid ();
return $Guid;
}
function toString ()
{
$raw = Strtoupper ($this->valueaftermd5);
Return substr ($raw, 0,8). ' -'. substr ($raw, 8,4). ' -'. substr ($raw, 12,4). ' -'. substr ($raw, 16,4). ' -'. substr ($raw, 20);
}
}

Guid class use Method:

Copy Code code as follows:

Require_once ("guid.class.php");
$Guid = new Guid ();
Print $Guid->tostring ();