The functions in this module try to guess the content type and encoding of a file by looking for certain magic byte sequences at specific positions within the file. While this is not a bullet proof approach the heuristics used do a very good job.
This extension is derivated from Apache mod_mime_magic, which is itself based on the file command maintaind by Ian F. Darwin. See the source code for further historic and copyright information.
You must compile PHP with the configure switch --with-mime-magic to get support for mime-type functions. The extension needs a copy of the simplified magic file that is distributed with the Apache httpd.
Замечание: The configure option has been changed from --enable-mime-magic to --with-mime-magic since PHP 4.3.2
Замечание: This extension is not capable of handling the fully decorated magic file that generally comes with standard Linux distro's and is supposed to be used with recent versions of file command.
Поведение этих функций находится в зависимости от установок в php.ini.
Таблица 1. Mimetype configuration options