com_create_guid

(PHP 5, PHP 7, PHP 8)

com_create_guidGera um identificador único global (GUID)

Descrição

com_create_guid(): string|false

Gera um identificador único global (GUID).

Um GUID é gerado da mesma maneira que os UUIDs do DCE, exceto que a convenção da Microsoft é colocar um GUID entre chaves.

Parâmetros

Esta função não possui parâmetros.

Valor Retornado

Retorna o GUID como uma string, ou false em caso de falha.

Veja Também

  • uuid_create() na extensão uuid PECL

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User Contributed Notes 5 notes

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34
Dave Pearson (dave at pds-uk dot com)
8 years ago
Here's my final version of a GUIDv4 function (based on others work here) that should work on all platforms and gracefully fallback to less cryptographically secure version if others are not supported...

<?php
/**
* Returns a GUIDv4 string
*
* Uses the best cryptographically secure method
* for all supported pltforms with fallback to an older,
* less secure version.
*
* @param bool $trim
* @return string
*/
function GUIDv4 ($trim = true)
{
// Windows
if (function_exists('com_create_guid') === true) {
if (
$trim === true)
return
trim(com_create_guid(), '{}');
else
return
com_create_guid();
}

// OSX/Linux
if (function_exists('openssl_random_pseudo_bytes') === true) {
$data = openssl_random_pseudo_bytes(16);
$data[6] = chr(ord($data[6]) & 0x0f | 0x40); // set version to 0100
$data[8] = chr(ord($data[8]) & 0x3f | 0x80); // set bits 6-7 to 10
return vsprintf('%s%s-%s-%s-%s-%s%s%s', str_split(bin2hex($data), 4));
}

// Fallback (PHP 4.2+)
mt_srand((double)microtime() * 10000);
$charid = strtolower(md5(uniqid(rand(), true)));
$hyphen = chr(45); // "-"
$lbrace = $trim ? "" : chr(123); // "{"
$rbrace = $trim ? "" : chr(125); // "}"
$guidv4 = $lbrace.
substr($charid, 0, 8).$hyphen.
substr($charid, 8, 4).$hyphen.
substr($charid, 12, 4).$hyphen.
substr($charid, 16, 4).$hyphen.
substr($charid, 20, 12).
$rbrace;
return
$guidv4;
}
?>
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39
Alix Axel
14 years ago
The phunction PHP framework (http://sourceforge.net/projects/phunction/) uses the following function to generate valid version 4 UUIDs:

<?php

function GUID()
{
if (
function_exists('com_create_guid') === true)
{
return
trim(com_create_guid(), '{}');
}

return
sprintf('%04X%04X-%04X-%04X-%04X-%04X%04X%04X', mt_rand(0, 65535), mt_rand(0, 65535), mt_rand(0, 65535), mt_rand(16384, 20479), mt_rand(32768, 49151), mt_rand(0, 65535), mt_rand(0, 65535), mt_rand(0, 65535));
}

?>

The output generated by the sprintf() and mt_rand() calls is identical to com_create_guid() results.
up
28
pavel.volyntsev(at)gmail
9 years ago
Use more cryptographically strong algorithm to generate pseudo-random bytes and format it as GUID v4 string

function guidv4()
{
if (function_exists('com_create_guid') === true)
return trim(com_create_guid(), '{}');

$data = openssl_random_pseudo_bytes(16);
$data[6] = chr(ord($data[6]) & 0x0f | 0x40); // set version to 0100
$data[8] = chr(ord($data[8]) & 0x3f | 0x80); // set bits 6-7 to 10
return vsprintf('%s%s-%s-%s-%s-%s%s%s', str_split(bin2hex($data), 4));
}
up
11
indrora
8 years ago
If you're going to generate random UUIDs, at least make them conform:

* The uppermost byte of the third stanza must be 4
* the uppermost byte of the fourth stanza may be any of (8 9 a b)

see also: The wikipedia page for UUIDs: https://en.wikipedia.org/wiki/Universally_unique_identifier#Version_4_.28random.29
up
0
internmail (at the google mail).com
4 years ago
function create_guid() { // Create GUID (Globally Unique Identifier)
$guid = '';
$namespace = rand(11111, 99999);
$uid = uniqid('', true);
$data = $namespace;
$data .= $_SERVER['REQUEST_TIME'];
$data .= $_SERVER['HTTP_USER_AGENT'];
$data .= $_SERVER['REMOTE_ADDR'];
$data .= $_SERVER['REMOTE_PORT'];
$hash = strtoupper(hash('ripemd128', $uid . $guid . md5($data)));
$guid = substr($hash, 0, 8) . '-' .
substr($hash, 8, 4) . '-' .
substr($hash, 12, 4) . '-' .
substr($hash, 16, 4) . '-' .
substr($hash, 20, 12);
return $guid;
}
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