检查此方法是否适用于唯一ID

Question

I'm trying to create ids to diversified contents using md5 to encode but, I'm not sure about this method.

<?php    
$prefix = 'stackoverflow';
$length = 11;
$id = md5( $prefix . uniqid(microtime()) );

$part1 = substr($id, 0,(floor($length / 2))); //First 5 chars

$id = strrev($id); //Reverse md5

$part2 = substr($id, 0,(ceil($length / 2))); //First 6 chars of the reversed md5

$final_id = $part2 . $part1; //Reverse final id
?>

Answer 1

You're trying to reinvent a wheel.

http://www.php.net/manual/en/function.uniqid.php

string uniqid ([ string $prefix = "" [, bool $more_entropy = false ]] )

Gets a prefixed unique identifier based on the current time in microseconds.

Also you might want to use real globally unique identifiers (windows specific extension)

http://www.php.net/manual/en/function.com-create-guid.php