How do I get a file extension in PHP?

Question

This is a question you can read everywhere on the web with various answers:

$ext = end(explode(\'.\', $filename));
$ext = substr(strrchr($filename, \'.\'), 1         


        

Answer 1

E-satis's response is the correct way to determine the file extension.

Alternatively, instead of relying on a files extension, you could use the fileinfo to determine the files MIME type.

Here's a simplified example of processing an image uploaded by a user:

// Code assumes necessary extensions are installed and a successful file upload has already occurred

// Create a FileInfo object
$finfo = new FileInfo(null, '/path/to/magic/file');

// Determine the MIME type of the uploaded file
switch ($finfo->file($_FILES['image']['tmp_name'], FILEINFO_MIME)) {        
    case 'image/jpg':
        $im = imagecreatefromjpeg($_FILES['image']['tmp_name']);
    break;

    case 'image/png':
        $im = imagecreatefrompng($_FILES['image']['tmp_name']);
    break;

    case 'image/gif':
        $im = imagecreatefromgif($_FILES['image']['tmp_name']);
    break;
}