Comments on: Generating MIME Type in PHP is not Magic

By: PHP MIME

PHP MIME — Fri, 16 Mar 2012 08:20:00 +0000

Thank you a lot for writing this helpful article.
Have a nice day.

By: Chris Jean

Chris Jean — Tue, 10 Jan 2012 19:37:19 +0000

Does your comment have anything to do with what I’m talking about in this post, or are you simply looking for someone to help you fix your code?

If you read this post, I talk about why the finfo_open() may not be available on all systems.

By: sunday igoche

sunday igoche — Tue, 10 Jan 2012 19:30:46 +0000

Fatal error: Call to undefined function finfo_open() in C:\wamp\www\testing\test.php on line 47

the code in line 47 is: $finfo = finfo_open(FILEINFO_MIME_TYPE);

please help.

By: Michele

Michele — Sat, 10 Dec 2011 21:26:45 +0000

You have made my day. Thank you

By: Get MIME type of file using PHP | Aqua Smit

Get MIME type of file using PHP | Aqua Smit — Fri, 07 Oct 2011 09:11:29 +0000

[...] http://chrisjean.com/2009/02/14/generating-mime-type-in-php-is-not-magic/ This entry was posted in Uncategorized by admin. Bookmark the permalink. [...]

By: gaarai

gaarai — Mon, 30 Aug 2010 21:01:10 +0000

Relying on the “file” program is a severe code portability issue. Failure would easily occur if the system does not have the file program, the file program uses a different parameter syntax, or the platform does not support the program (Windows).

By: devsforev

devsforev — Thu, 26 Aug 2010 16:05:04 +0000

Thank you for this nice workaround! I too was struggling yesterday with determining the mime-type. It’s for a script that sends email attachments. My GoDaddy host runs PHP 5.2.8, so FileInfo was not available, and mime_content_type did not exist either. Another trick I’ve used in the past:

exec(file -bi $file);

Didn’t work either :-/. Apparently the “file” program is not installed on my host… Your workaround solved my problems. Thanks!

By: gaarai

gaarai — Thu, 19 Aug 2010 13:55:35 +0000

As noted in the post, PHP’s advanced functions can determine type by content. Reproducing that would be tedious, expensive, and error-prone in pure PHP. The code provided here is to establish a baseline set of code that can be reliably distributed to unknown platforms without fear of catastrophic failure if the system does not support the functions provided by default builds or more recent versions of PHP. In other words, it is a compatibility method combined with a best-effort algorithm.

In the case of this function running without support for the PHP functions for a filename with no matching extension, the last_resort method of the function will return “application/octet-stream”. While this may not be the desired outcome, it will still generate a valid generic MIME type.

Your scenario of a filename without an extension shows a weakness in this approach; however, it should also be noted that a file of type JPEG with an extension of png will receive a MIME type of “image/png” rather than “image/jpeg”. This scenario is potentially worse than the one you brought up as the MIME type in this scenario is wrong whereas your scenario’s result of the “application/octet-stream” MIME type is generic yet valid. Of course if a text file is called “converting.gif.to.jpg”, it would also improperly receive a MIME type of “image/jpeg”.

For my applications, such failings are acceptable as MIME type recognition should always be considered suggestions as even the advanced PHP MIME functions have situations where they identify files properly. If this is unacceptable for your application, you either need to come up with a different solution or rethink your application’s reliance on MIME type identification.

By: Eddie

Eddie — Thu, 19 Aug 2010 13:34:37 +0000

Your code fails to detect MIME types at all when the file does not have an extension and neither finfo_openn or mime_content_type are available.

How do you propose that?

By: acatalept

acatalept — Tue, 04 May 2010 15:59:48 +0000

Outstanding… I’ve been hitting a brick wall getting mime types working after upgrading to PHP 5.3 (still says “undefined function finfo_open()” strangely enough).

Very elegant, portable solution. Thanks!