PHP uniqid function written in pure PHP

uniqid.php

<?php

/*
 * Use this if you need to recreate `uniqid` in another language
 * From: http://php.net/manual/en/function.uniqid.php#95001
 */

//  time in microseconds as float
$m = microtime(true);

// show me the results
echo sprintf("%8x%05x\n", floor($m), ($m - floor($m)) * 1000000);

// show me the real call to `uniqid`
echo uniqid();

Note, the newline is not part of the uniqid function:

echo sprintf("%8x%05x", floor($m), ($m - floor($m)) * 1000000) . "\n";