This is a port of Apache2 mod_mime_magic.c in Perl, written in XS with the 
aim of being efficient and fast especially for applications that need to 
be run for an extended amount of time.

There is a compatibility layer for File::MMagic. you can specify :compat 
when importing the module

   use File::MMagic::XS qw(:compat);

And then the following methods are going to be available from 
File::MMagic::XS:

   checktype_filename
   checktype_filehandle
   checktype_contents
   addMagicEntry

Currently this software is in beta. If you have 
suggestions/recommendations about the interface or anything else, now is 
your chance to send them!

WWW: http://search.cpan.org/dist/File-MMagic-XS