这是我到目前为止所提出的，我认为这是一个更优雅的解决方案：
/**
* Converts a human readable file size value to a number of bytes that it
* represents. Supports the following modifiers: K, M, G and T.
* Invalid input is returned unchanged.
*
* Example:
*
* $config->human2byte(10); // 10
* $config->human2byte('10b'); // 10
* $config->human2byte('10k'); // 10240
* $config->human2byte('10K'); // 10240
* $config->human2byte('10kb'); // 10240
* $config->human2byte('10Kb'); // 10240
* // and even
* $config->human2byte(' 10 KB '); // 10240
*
*
* @param number|string $value
* @return number
*/
public function human2byte($value) {
return preg_replace_callback('/^\s*(\d+)\s*(?:([kmgt]?)b?)?\s*$/i', function ($m) {
switch (strtolower($m[2])) {
case 't': $m[1] *= 1024;
case 'g': $m[1] *= 1024;
case 'm': $m[1] *= 1024;
case 'k': $m[1] *= 1024;
}
return $m[1];
}, $value);
}