guessExtension()

[nowackipawel]

Am I wrong or this code does not have sense:

	public static function guessExtensionFromType(string $type) // $type contains MIME TYPE like 'image/jpeg'
	{
		$type = trim(strtolower($type), '. ');

		foreach (self::$mimes as $ext => $types)
		{
			if (is_string($types) && $types == $type)
			{
				return $ext;
			}
			else if (is_array($types) && in_array($type, $types))
			{
				return $ext;
			}
		}

		return null;
	}

for extensions like, i.e.:

	public static $mimes = [

		'mid'   => 'audio/midi',
		'midi'  => 'audio/midi',
		'mpga'  => 'audio/mpeg',
		'mp2'   => 'audio/mpeg',

		'jpg'   => ['image/jpeg', 'image/pjpeg'],
		'jpeg'  => ['image/jpeg', 'image/pjpeg'],
		'jpe'   => ['image/jpeg', 'image/pjpeg'],
		'jp2'   => ['image/jp2', 'video/mj2', 'image/jpx', 'image/jpm'],
		'j2k'   => ['image/jp2', 'video/mj2', 'image/jpx', 'image/jpm'],
		'jpf'   => ['image/jp2', 'video/mj2', 'image/jpx', 'image/jpm'],
		'jpg2'  => ['image/jp2', 'video/mj2', 'image/jpx', 'image/jpm'],
		'jpx'   => ['image/jp2', 'video/mj2', 'image/jpx', 'image/jpm'],
		'jpm'   => ['image/jp2', 'video/mj2', 'image/jpx', 'image/jpm'],
		'mj2'   => ['image/jp2', 'video/mj2', 'image/jpx', 'image/jpm'],
		'mjp2'  => ['image/jp2', 'video/mj2', 'image/jpx', 'image/jpm'],
];

for image/jpeg it always returns 'jpg' even if real file extension is jpeg or jpe which are also correct;

[lonnieezell]

The purpose of that method is to attempt to reliably guess the file type based on the mime type of the file itself, not a user supplied input. In the case of this example - jpg, jpeg, and jpe are all the same file format and just different variations based on different common uses. But renaming it from jpeg to jpg will have no affect to the usability of the file.