Mimetype Functions

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# LVII. Mimetype Functions

# Introduction

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.

# Requirements

No external libraries are needed to build this extension.

# Installation

The extension needs a copy of the `magic.mime` as distributed with the `file` command. This file also part of most recent Linux distributions and usually stored in the `/usr/share/misc` directory.

# Runtime Configuration

The behaviour of these functions is affected by settings in `php.ini`.

Table 1. Mimetype configuration options

Name | Default | Changeable
--- | --- | ---
mime_magic.magicfile | "/usr/share/misc/magic.mime" | PHP_INI_SYSTEM

For further details and definition of the PHP_INI_* constants see ini_set().

# Resource Types

This extension has no resource types defined.

# Predefined Constants

This extension has no constants defined.

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