Ok, so I have an index.php file which has to process many different file types. how do I guess the filetype based on the REQUEST_URI.
If I request http://site/image.jpg, and all requests redirect through index.php, which looks like this
<?php
include('/www/site'.$_SERVER['REQUEST_URI']);
?>
How would I make that work correctly?
Should I test based on the extension of the file requested, or is there a way to get the filetype?
In Urlmon.dll, there's a function called FindMimeFromData.
From the documentation
MIME type detection, or "data sniffing," refers to the process of determining an appropriate MIME type from binary data. The final result depends on a combination of server-supplied MIME type headers, file extension, and/or the data itself. Usually, only the first 256 bytes of data are significant.
So, read the first (up to) 256 bytes from the file and pass it to FindMimeFromData.
.NET's mime-type mappings are stored in the System.Web.MimeMapping class which offers the GetMimeMapping method.
Prior to .NET 4.5, this class was marked as internal, and thus not available to your code. In that case the best you can do is steal the list, which you can get using Reflector and decompile the static constructor (cctor).
If taking that approach, you may be better off simply creating a list of supported extensions and their mime type and storing it on a dictionary. (The list inside MimeMapping is a tad verbose)
Case-insensitive.
Hypertext Transfer Protocol -- HTTP/1.1:
4.2 Message Headers
HTTP header fields, which include general-header (section 4.5), request-header (section 5.3), response-header (section 6.2), and entity-header (section 7.1) fields, follow the same generic format as that given in Section 3.1 of RFC 822 [9]. Each header field consists of a name followed by a colon (":") and the field value. Field names are case-insensitive.
If you are sure you're only ever working with images, you can check out the
getimagesize()exif_imagetype() PHP function, which attempts to return the image mime-type.If you don't mind external dependencies, you can also check out the excellent getID3 library which can determine the mime-type of many different file types.
Lastly, you can check out the mime_content_type() function - but it has been deprecated for the Fileinfo PECL extension.