gnu-social/extlib/MIME/Type.php

<?php
/* vim: set expandtab tabstop=4 shiftwidth=4: */
// +----------------------------------------------------------------------+
// | PHP version 4                                                        |
// +----------------------------------------------------------------------+
// | Copyright (c) 1997-2002, 2008 The PHP Group                                |
// +----------------------------------------------------------------------+
// | This source file is subject to version 3.0 of the PHP license,       |
// | that is bundled with this package in the file LICENSE, and is        |
// | available at through the world-wide-web at                           |
// | http://www.php.net/license/3_0.txt.                                  |
// | If you did not receive a copy of the PHP license and are unable to   |
// | obtain it through the world-wide-web, please send a note to          |
// | license@php.net so we can mail you a copy immediately.               |
// +----------------------------------------------------------------------+
// | Authors: Ian Eure <ieure@php.net>                                    |
// +----------------------------------------------------------------------+
//
// $Id: Type.php,v 1.6 2009/01/16 11:49:45 cweiske Exp $

require_once 'PEAR.php';

$_fileCmd = &PEAR::getStaticProperty('MIME_Type', 'fileCmd');
$_fileCmd = 'file';

/**
 * Class for working with MIME types
 *
 * @category MIME
 * @package  MIME_Type
 * @license  PHP License 3.0
 * @version  1.2.0
 * @link     http://pear.php.net/package/MIME_Type
 * @author   Ian Eure <ieure@php.net>
 */
class MIME_Type
{
    /**
     * The MIME media type
     *
     * @var string
     */
    var $media = '';

    /**
     * The MIME media sub-type
     *
     * @var string
     */
    var $subType = '';

    /**
     * Optional MIME parameters
     *
     * @var array
     */
    var $parameters = array();

    /**
     * List of valid media types.
     * A media type is the string in front of the slash.
     * The media type of "text/xml" would be "text".
     *
     * @var array
     */
    var $validMediaTypes = array(
        'text',
        'image',
        'audio',
        'video',
        'application',
        'multipart',
        'message'
    );


    /**
     * Constructor.
     *
     * If $type is set, if will be parsed and the appropriate class vars set.
     * If not, you get an empty class.
     * This is useful, but not quite as useful as parsing a type.
     *
     * @param string $type MIME type
     *
     * @return void
     */
    function MIME_Type($type = false)
    {
        if ($type) {
            $this->parse($type);
        }
    }


    /**
     * Parse a mime-type and set the class variables.
     *
     * @param string $type MIME type to parse
     *
     * @return void
     */
    function parse($type)
    {
        $this->media      = $this->getMedia($type);
        $this->subType    = $this->getSubType($type);
        $this->parameters = array();
        if (MIME_Type::hasParameters($type)) {
            require_once 'MIME/Type/Parameter.php';
            foreach (MIME_Type::getParameters($type) as $param) {
                $param = new MIME_Type_Parameter($param);
                $this->parameters[$param->name] = $param;
            }
        }
    }


    /**
     * Does this type have any parameters?
     *
     * @param string $type MIME type to check
     *
     * @return boolean true if $type has parameters, false otherwise
     * @static
     */
    function hasParameters($type)
    {
        if (strstr($type, ';')) {
            return true;
        }
        return false;
    }


    /**
     * Get a MIME type's parameters
     *
     * @param string $type MIME type to get parameters of
     *
     * @return array $type's parameters
     * @static
     */
    function getParameters($type)
    {
        $params = array();
        $tmp    = explode(';', $type);
        for ($i = 1; $i < count($tmp); $i++) {
            $params[] = trim($tmp[$i]);
        }
        return $params;
    }


    /**
     * Strip parameters from a MIME type string.
     *
     * @param string $type MIME type string
     *
     * @return string MIME type with parameters removed
     * @static
     */
    function stripParameters($type)
    {
        if (strstr($type, ';')) {
            return substr($type, 0, strpos($type, ';'));
        }
        return $type;
    }


    /**
     * Removes comments from a media type, subtype or parameter.
     *
     * @param string $string   String to strip comments from
     * @param string &$comment Comment is stored in there.
     *
     * @return string   String without comments
     * @static
     */
    function stripComments($string, &$comment)
    {
        if (strpos($string, '(') === false) {
            return $string;
        }

        $inquote   = false;
        $quoting   = false;
        $incomment = 0;
        $newstring = '';

        for ($n = 0; $n < strlen($string); $n++) {
            if ($quoting) {
                if ($incomment == 0) {
                    $newstring .= $string[$n];
                } else if ($comment !== null) {
                    $comment .= $string[$n];
                }
                $quoting = false;
            } else if ($string[$n] == '\\') {
                $quoting = true;
            } else if (!$inquote && $incomment > 0 && $string[$n] == ')') {
                $incomment--;
                if ($incomment == 0 && $comment !== null) {
                    $comment .= ' ';
                }
            } else if (!$inquote && $string[$n] == '(') {
                $incomment++;
            } else if ($string[$n] == '"') {
                if ($inquote) {
                    $inquote = false;
                } else {
                    $inquote = true;
                }
            } else if ($incomment == 0) {
                $newstring .= $string[$n];
            } else if ($comment !== null) {
                $comment .= $string[$n];
            }
        }

        if ($comment !== null) {
            $comment = trim($comment);
        }

        return $newstring;
    }


    /**
     * Get a MIME type's media
     *
     * @note 'media' refers to the portion before the first slash
     *
     * @param string $type MIME type to get media of
     *
     * @return string $type's media
     * @static
     */
    function getMedia($type)
    {
        $tmp = explode('/', $type);
        return strtolower(trim(MIME_Type::stripComments($tmp[0], $null)));
    }


    /**
     * Get a MIME type's subtype
     *
     * @param string $type MIME type to get subtype of
     *
     * @return string $type's subtype, null if invalid mime type
     * @static
     */
    function getSubType($type)
    {
        $tmp = explode('/', $type);
        if (!isset($tmp[1])) {
            return null;
        }
        $tmp = explode(';', $tmp[1]);
        return strtolower(trim(MIME_Type::stripComments($tmp[0], $null)));
    }


    /**
     * Create a textual MIME type from object values
     *
     * This function performs the opposite function of parse().
     *
     * @return string MIME type string
     */
    function get()
    {
        $type = strtolower($this->media . '/' . $this->subType);
        if (count($this->parameters)) {
            foreach ($this->parameters as $key => $null) {
                $type .= '; ' . $this->parameters[$key]->get();
            }
        }
        return $type;
    }


    /**
     * Is this type experimental?
     *
     * @note Experimental types are denoted by a leading 'x-' in the media or
     *       subtype, e.g. text/x-vcard or x-world/x-vrml.
     *
     * @param string $type MIME type to check
     *
     * @return boolean true if $type is experimental, false otherwise
     * @static
     */
    function isExperimental($type)
    {
        if (substr(MIME_Type::getMedia($type), 0, 2) == 'x-' ||
            substr(MIME_Type::getSubType($type), 0, 2) == 'x-') {
            return true;
        }
        return false;
    }


    /**
     * Is this a vendor MIME type?
     *
     * @note Vendor types are denoted with a leading 'vnd. in the subtype.
     *
     * @param string $type MIME type to check
     *
     * @return boolean true if $type is a vendor type, false otherwise
     * @static
     */
    function isVendor($type)
    {
        if (substr(MIME_Type::getSubType($type), 0, 4) == 'vnd.') {
            return true;
        }
        return false;
    }


    /**
     * Is this a wildcard type?
     *
     * @param string $type MIME type to check
     *
     * @return boolean true if $type is a wildcard, false otherwise
     * @static
     */
    function isWildcard($type)
    {
        if ($type == '*/*' || MIME_Type::getSubtype($type) == '*') {
            return true;
        }
        return false;
    }


    /**
     * Perform a wildcard match on a MIME type
     *
     * Example:
     * MIME_Type::wildcardMatch('image/*', 'image/png')
     *
     * @param string $card Wildcard to check against
     * @param string $type MIME type to check
     *
     * @return boolean true if there was a match, false otherwise
     * @static
     */
    function wildcardMatch($card, $type)
    {
        if (!MIME_Type::isWildcard($card)) {
            return false;
        }

        if ($card == '*/*') {
            return true;
        }

        if (MIME_Type::getMedia($card) == MIME_Type::getMedia($type)) {
            return true;
        }

        return false;
    }


    /**
     * Add a parameter to this type
     *
     * @param string $name    Attribute name
     * @param string $value   Attribute value
     * @param string $comment Comment for this parameter
     *
     * @return void
     */
    function addParameter($name, $value, $comment = false)
    {
        $tmp = new MIME_Type_Parameter();

        $tmp->name               = $name;
        $tmp->value              = $value;
        $tmp->comment            = $comment;
        $this->parameters[$name] = $tmp;
    }


    /**
     * Remove a parameter from this type
     *
     * @param string $name Parameter name
     *
     * @return void
     */
    function removeParameter($name)
    {
        unset($this->parameters[$name]);
    }


    /**
     * Autodetect a file's MIME-type
     *
     * This function may be called staticly.
     *
     * @internal Tries to use fileinfo extension at first. If that
     *  does not work, mime_magic is used. If this is also not available
     *  or does not succeed, "file" command is tried to be executed with
     *  System_Command. When that fails, too, then we use our in-built
     *  extension-to-mimetype-mapping list.
     *
     * @param string $file   Path to the file to get the type of
     * @param bool   $params Append MIME parameters if true
     *
     * @return string $file's MIME-type on success, PEAR_Error otherwise
     *
     * @since 1.0.0beta1
     * @static
     */
    function autoDetect($file, $params = false)
    {
        // Sanity checks
        if (!file_exists($file)) {
            return PEAR::raiseError("File \"$file\" doesn't exist");
        }

        if (!is_readable($file)) {
            return PEAR::raiseError("File \"$file\" is not readable");
        }

        if (function_exists('finfo_file')) {
            $finfo = finfo_open(FILEINFO_MIME);
            $type  = finfo_file($finfo, $file);
            finfo_close($finfo);
            if ($type !== false && $type !== '') {
                return MIME_Type::_handleDetection($type, $params);
            }
        }

        if (function_exists('mime_content_type')) {
            $type = mime_content_type($file);
            if ($type !== false && $type !== '') {
                return MIME_Type::_handleDetection($type, $params);
            }
        }

        @include_once 'System/Command.php';
        if (class_exists('System_Command')) {
            return MIME_Type::_handleDetection(
                MIME_Type::_fileAutoDetect($file),
                $params
            );
        }

        require_once 'MIME/Type/Extension.php';
        $mte = new MIME_Type_Extension();
        return $mte->getMIMEType($file);
    }


    /**
     * Handles a detected MIME type and modifies it if necessary.
     *
     * @param string $type   MIME Type of a file
     * @param bool   $params Append MIME parameters if true
     *
     * @return string $file's MIME-type on success, PEAR_Error otherwise
     */
    function _handleDetection($type, $params)
    {
        // _fileAutoDetect() may have returned an error.
        if (PEAR::isError($type)) {
            return $type;
        }

        // Don't return an empty string
        if (!$type || !strlen($type)) {
            return PEAR::raiseError("Sorry, couldn't determine file type.");
        }

        // Strip parameters if present & requested
        if (MIME_Type::hasParameters($type) && !$params) {
            $type = MIME_Type::stripParameters($type);
        }

        return $type;
    }


    /**
     * Autodetect a file's MIME-type with 'file' and System_Command
     *
     * This function may be called staticly.
     *
     * @param string $file Path to the file to get the type of
     *
     * @return string $file's MIME-type
     *
     * @since 1.0.0beta1
     * @static
     */
    function _fileAutoDetect($file)
    {
        $cmd = new System_Command();

        // Make sure we have the 'file' command.
        $fileCmd = PEAR::getStaticProperty('MIME_Type', 'fileCmd');
        if (!$cmd->which($fileCmd)) {
            unset($cmd);
            return PEAR::raiseError("Can't find file command \"{$fileCmd}\"");
        }

        $cmd->pushCommand($fileCmd, "-bi " . escapeshellarg($file));
        $res = $cmd->execute();
        unset($cmd);

        return $res;
    }
}