generate random fixed length codes

code.php

#!/usr/bin/php
<?php
if (count($argv) === 1 OR count($argv) < 5)
{
	echo "Usage: code.php <number_of_codes> <lenght_of_code> <separator> <prefix>\n"; die;
}

$number_of_codes = $argv[1];
$lenght_of_code = $argv[2];
$separator = $argv[3];
$prefix = $argv[4];


$codes = array();

while (count($codes) <$number_of_codes)
{
	$code = $prefix.substr(md5(microtime()),rand(0,26),$lenght_of_code);		
	if (in_array($code, $codes))
		continue;
	else
		array_push($codes, $code);
}
$codes = array_unique($codes);
 
foreach($codes as $code)
{
	echo $code.$separator;
}
?>