How to get the content-type of a file in PHP?

Question

I'm using PHP to send an email with an attachment. The attachment could be any of several different file types (pdf, txt, doc, swf, etc).

First, the script gets the file using "file_get_contents".

Later, the script echoes in the header:

Content-Type: <?php echo $the_content_type; ?>; name="<?php echo $the_file_name; ?>"

How to I set the correct value for $the_content_type?

deceze · Answer 1 · 2011-09-08T07:43:26.323

I am using this function, which includes several fallbacks to compensate for older versions of PHP or simply bad results:

function getFileMimeType($file) {
    if (function_exists('finfo_file')) {
        $finfo = finfo_open(FILEINFO_MIME_TYPE);
        $type = finfo_file($finfo, $file);
        finfo_close($finfo);
    } else {
        require_once 'upgradephp/ext/mime.php';
        $type = mime_content_type($file);
    }

    if (!$type || in_array($type, array('application/octet-stream', 'text/plain'))) {
        $secondOpinion = exec('file -b --mime-type ' . escapeshellarg($file), $foo, $returnCode);
        if ($returnCode === 0 && $secondOpinion) {
            $type = $secondOpinion;
        }
    }

    if (!$type || in_array($type, array('application/octet-stream', 'text/plain'))) {
        require_once 'upgradephp/ext/mime.php';
        $exifImageType = exif_imagetype($file);
        if ($exifImageType !== false) {
            $type = image_type_to_mime_type($exifImageType);
        }
    }

    return $type;
}

It tries to use the newer PHP finfo functions. If those aren't available, it uses the mime_content_type alternative and includes the drop-in replacement from the Upgrade.php library to make sure this exists. If those didn't return anything useful, it'll try the OS' file command. AFAIK that's only available on *NIX systems, you may want to change that or get rid of it if you plan to use this on Windows. If nothing worked, it tries exif_imagetype as fallback for images only.

I have come to notice that different servers vary widely in their support for the mime type functions, and that the Upgrade.php mime_content_type replacement is far from perfect. The limited exif_imagetype functions, both the original and the Upgrade.php replacement, are working pretty reliably though. If you're only concerned about images, you may only want to use this last one.

The fallback to the `file` command is redundant. The FileInfo extension (and mime_content_type function) use the same file detection database as the `file` command. — Sander Marechal, Jan 18 '11 at 07:31
@Sander In my tests I found `mime_content_type` to be somewhat unreliable, or possibly its upgrade.php replacement was, while the `file` call is usually successful. I'll have to look into this more to see when and why it fails under which circumstances. At least it does no harm being there. :) — deceze, Jan 18 '11 at 07:38
I had a quick look at the Upgrade.php code for mime_content_type. First it tries the FileInfo PECL extension. If that doesn't exist, it tries to parse the `magic` file by itself, in PHP. Problem: It only looks in a few predefined places for the `magic` file. It fails on my Debian Squeeze for example. It's also possible that the parser has bugs, but I didn't check that thoroughly. — Sander Marechal, Jan 18 '11 at 08:30
@Sander Yeah, I'm not entirely convinced of the quality of the upgrade.php library. As such, since even `mime_content_type` doesn't seem to be available everywhere, I think the fallback to `file` is appropriate. :) — deceze, Jan 18 '11 at 08:35
Yes. You're probably better off with just FileInfo and a fallback to `file`. — Sander Marechal, Jan 18 '11 at 09:46
When only detecting image type, I think using `exif_imagetype` by itself is the best approach. I tried using `finfo_file` and it worked *most* of the time, but sometimes it returned the type as being `application/octet-stream` instead of the correct file type. — Nate, Aug 02 '14 at 02:01

score 12 · Answer 2 · answered Jul 20 '16 at 08:27

It very easy to have it in php.

Simply call the following php function mime_content_type

<?php
    $filelink= 'uploads/some_file.pdf';
    $the_content_type = "";

    // check if the file exist before
    if(is_file($file_link)) {
        $the_content_type = mime_content_type($file_link);
    }
    // You can now use it here.

?>

PHP documentation of the function mime_content_type() Hope it helps someone

score 7 · Answer 3 · answered Aug 05 '09 at 11:55

7

With finfo_file: http://us2.php.net/manual/en/function.finfo-file.php

answered Aug 05 '09 at 11:55

Quentin

914,110
126
1,211
1,335

8

Getting the mime type of a file in PHP still is quite a pain in the a** ... ;-) – Philippe Gerber Aug 05 '09 at 12:14
1

11 years later and it's still horrible – Sliq Nov 24 '20 at 17:39

score 4 · Answer 4 · edited Jun 07 '11 at 17:04

4

Here's an example using finfo_open which is available in PHP5 and PECL:

$mimepath='/usr/share/magic'; // may differ depending on your machine
// try /usr/share/file/magic if it doesn't work
$mime = finfo_open(FILEINFO_MIME,$mimepath);
if ($mime===FALSE) {
 throw new Exception('Unable to open finfo');
}
$filetype = finfo_file($mime,$tmpFileName);
finfo_close($mime);
if ($filetype===FALSE) {
 throw new Exception('Unable to recognise filetype');
}

Alternatively, you can use the deprecated mime_ content_ type function:

$filetype=mime_content_type($tmpFileName);

or use the OS's in built functions:

ob_start();
system('/usr/bin/file -i -b ' . realpath($tmpFileName));
$type = ob_get_clean();
$parts = explode(';', $type);
$filetype=trim($parts[0]);

edited Jun 07 '11 at 17:04

Bill the Lizard

398,270
210
566
880

answered Aug 05 '09 at 12:06

Richy B.

1,619
12
20

3

mime_content_type is not deprecated. – Andrew Lalis Mar 26 '19 at 14:42
True - turns out the manual had it incorrectly marked as deprecated ( https://bugs.php.net/bug.php?id=71367 and https://stackoverflow.com/a/39676272/136771 ) – Richy B. Mar 27 '19 at 10:41

score 3 · Answer 5 · edited May 23 '17 at 12:10

function getMimeType( $filename ) {
        $realpath = realpath( $filename );
        if ( $realpath
                && function_exists( 'finfo_file' )
                && function_exists( 'finfo_open' )
                && defined( 'FILEINFO_MIME_TYPE' )
        ) {
                // Use the Fileinfo PECL extension (PHP 5.3+)
                return finfo_file( finfo_open( FILEINFO_MIME_TYPE ), $realpath );
        }
        if ( function_exists( 'mime_content_type' ) ) {
                // Deprecated in PHP 5.3
                return mime_content_type( $realpath );
        }
        return false;
}

This worked for me

Why is mime_content_type() deprecated in PHP?

score 1 · Answer 6 · answered Nov 21 '15 at 22:15

I guess that i found a short way. Get the image size using:

$infFil=getimagesize($the_file_name);

and

Content-Type: <?php echo $infFil["mime"] ?>; name="<?php echo $the_file_name; ?>"

The getimagesize returns an associative array which have a MIME key

I used it and it works

score 0 · Answer 7 · answered May 01 '17 at 10:39

I've tried most of the suggestions, but they all fail for me (I'm inbetween any usefull version of PHP apparantly. I ended up with the following function:

function getShellFileMimetype($file) {
    $type = shell_exec('file -i -b '. escapeshellcmd( realpath($_SERVER['DOCUMENT_ROOT'].$file)) );
    if( strpos($type, ";")!==false ){
        $type = current(explode(";", $type));
    }
    return $type;
}

score 0 · Answer 8 · answered Jul 28 '22 at 19:01

From string: $mediaType = (new \finfo(FILEINFO_MIME))->buffer($string)
From filename: $mediaType = (new \finfo(FILEINFO_MIME))->file($filename)

The ext-fileinfo module is required (usually it is preinstalled) for PHP.

FILEINFO_MIME - Return the mime type and mime encoding as defined by RFC 2045..

If you use composer, don't forget. to add the ext-fileinfo entry to composer.json

Documentation: https://www.php.net/manual/en/ref.fileinfo.php

score -3 · Answer 9 · answered Aug 05 '09 at 12:00

-3

I really recommend using a Framework like "CodeIgniter" for seinding Emails. Here is a Screencast about "Sending Emails with CodeIgniter" in only 18 Minutes.

http://net.tutsplus.com/videos/screencasts/codeigniter-from-scratch-day-3/

answered Aug 05 '09 at 12:00

Yes, I plan to use that in future. Thanks for the link. – edt Aug 05 '09 at 12:41

score -3 · Answer 10 · answered Sep 08 '10 at 04:27

try this:

function ftype($f) {
                    curl_setopt_array(($c = @curl_init((!preg_match("/[a-z]+:\/{2}(?:www\.)?/i",$f) ? sprintf("%s://%s/%s", "http" , $_SERVER['HTTP_HOST'],$f) :  $f))), array(CURLOPT_RETURNTRANSFER => 1, CURLOPT_HEADER => 1));
                        return(preg_match("/Type:\s*(?<mime_type>[^\n]+)/i", @curl_exec($c), $m) && curl_getinfo($c, CURLINFO_HTTP_CODE) != 404)  ? ($m["mime_type"]) : 0;

         }
echo ftype("http://img2.orkut.com/images/medium/1283204135/604747203/ln.jpg"); // print image/jpeg

How to get the content-type of a file in PHP?

10 Answers10

Linked

Related