PHP, How to get Mime Type - Mission Impossible?

Question

Is there any decent way in PHP to get the mime type?

I have been searching extensively the past few hours and it seems like there are three main ways, which each way having problems:

1. mime_content_type() This is deprecated, alot of the times not installed, and if installed will sometimes not find the mime.magic file.

2. file_info Wasn't installed on the hosts I tried, doesn't seem to have very good support. Is an extension (PECL).

3. shell_exec(file -ib . $file) Doesn't work on windows servers. I tried it on a linux server and it gave me "image/x-3ds2" for a php file. What the hell is that!!!

What is a good, almost bullet proof way to get the mime type of a file?

Answer 1

As workaround you can use the "mime.php" extension from http://upgradephp.berlios.de/ It simulates the mime_content_type() if not available. Made specifically for such cases.

You can install your private mime.magic file and force it with ini_set("mime_magic.magicfile"). This is recommended anyway, so you have the desired settings available.

Answer 2

Chris Jean has developed a function called get_file_mime_type that first tries to use the finfo_open method, then falls back to the mime_content_type , then finally falls back to a simple extension => mime_type array. It works well for me when the first two options were not available on my server. Beats having to write the function myself!

Answer 3

You can use the magic numbers , consult some other file signature lists ( like this one here ), and then check the binary data for the first byte .

function getfiletype($file) {
    $handle = @fopen($file, 'r');
    if (!$handle)
        throw new Exception('File error - Can not open File or file missing');

    $types = array( 'jpeg' => "\xFF\xD8\xFF", 
                    'gif' => 'GIF',
                    'bmp' => 'BM',
                    'tiff' => '\x49\x20\x49',
                    'png' => "\x89\x50\x4e\x47\x0d\x0a",
                    'psd' => '8BPS', 
                    'swf' => 'FWS');

    $bytes = fgets($handle, 8);
    $filetype = 'other';

    foreach ( $types as $type => $header ) {
        if ( strpos( $bytes, $header ) === 0) {
            $filetype = $type;
            break;
        }
    }
    fclose($handle);
    return $filetype;
}

This is actually a very simple replacement function for file_info(), which operates in much the same way but on a much extended ( and lower ) level .

Alternative is using an already made external php class like this one for example ..