Determine file type

Franz · 2009-02-06 18:38:51

Does anybody out there know how I can determine the MIME type of a file? The mime_* functions won't work from PHP 5.3.* on, the fileinfo extension is an extension and therefore not always available and the extension doesn't necessary tell me the MIME type. Is there any other option?

If nobody knows one, it would be enough to differentiate between text files, image files and other (binary) files. Any ideas?

Thanks in advance

Last edited by Franz (2009-02-06 18:44:19)

FSX · 2009-02-06 18:53:42

I always use the extension to identify a file.

function get_ext($filepath)
{
    $explode = explode('.', $filepath);
    return $explode[count($explode)-1];
}

Last edited by FSX (2009-02-06 18:54:09)

Franz · 2009-02-06 18:57:49

As I said, that's not safe enough.

FSX · 2009-02-06 20:21:19

Well for images I use getimagesize(), but that's only for images.

Reines · 2009-02-07 01:09:27

fileinfo is part of PHP since 5.3.0, hence the removal of mime_content_type, so just check for the existence of 1 and if it doesn't exist then use the other.

Saying that, I don't like fileinfo at all, I think they have gone totally backwards with that :s

Franz · 2009-02-07 17:44:42

mime_content_type is disabled by default, I believe. So that's not safe either. It's possible to determine the file type when uploading files, so why not here?

Is there a way to read the actual file header?

Also: how can I recognize binary files?

Ruckus · 2009-02-10 12:17:11

I use this function. It attempts to use the FileInfo module if its loaded, otherwise it trys the mime_content_type, and as a fall back it uses a shell command. Because of what I'm using the function for, it takes some special cases into account and returns specific mime types if the extensions match.

    public function getMimeType($file){
        $type = 'application/octet-stream';
        if(function_exists('finfo_open')){ // Pecl
            $finfo = finfo_open(FILEINFO_MIME);
            $type = finfo_file($finfo, $file);
            finfo_close($finfo);
        }elseif(function_exists('mime_content_type')){ //attempt deprecated mime_content_type
            $type = mime_content_type($file);
        }else{ //attempt to use a shell command
            $type = shell_exec('file -i -b '.escapeshellarg($file));
            $type = explode(' ', $type);
            if(is_array($type))
                $type = $type[0];
        }
        if(substr($type, 0, 5) == 'text/'){
            $ext = strtolower(substr($file, strrpos($file, '.')));
            if($ext == '.php'){
                $type = 'application/x-httpd-php';
            }elseif($ext == '.phps'){
                $type = 'application/x-httpd-php-source';
            }elseif($ext == '.css'){
                $type = 'text/css';
            }elseif($ext == '.js'){
                $type = 'text/javascript';
            }
        }
        return $type;
    }

Franz · 2009-02-10 16:47:55

Thank you. I'll try it out. Is there absolutely no safe method?

Forums

#1 2009-02-06 18:38:51

Determine file type

#2 2009-02-06 18:53:42

Re: Determine file type

#3 2009-02-06 18:57:49

Re: Determine file type

#4 2009-02-06 20:21:19

Re: Determine file type

#5 2009-02-07 01:09:27

Re: Determine file type

#6 2009-02-07 17:44:42

Re: Determine file type

#7 2009-02-10 12:17:11

Re: Determine file type

#8 2009-02-10 16:47:55

Re: Determine file type

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