source: Dev/branches/cakephp/cake/libs/magic_db.php @ 126

<?php
/**
 * MagicDb parser and file analyzer
 *
 * PHP versions 4 and 5
 *
 * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
 * Copyright 2005-2011, Cake Software Foundation, Inc. (http://cakefoundation.org)
 *
 * Licensed under The MIT License
 * Redistributions of files must retain the above copyright notice.
 *
 * @copyright     Copyright 2005-2011, Cake Software Foundation, Inc. (http://cakefoundation.org)
 * @link          http://cakephp.org CakePHP(tm) Project
 * @package       cake
 * @subpackage    cake.cake.libs
 * @since         CakePHP(tm) v 1.2.0
 * @license       MIT License (http://www.opensource.org/licenses/mit-license.php)
 */
if (!class_exists('Object')) {
        require LIBS . 'object.php';
}
if (!class_exists('File')) {
        require LIBS . 'file.php';
}

/**
 * A class to parse and use the MagicDb for file type analysis
 *
 * @package       cake.tests
 * @subpackage    cake.tests.cases.libs
 */
class MagicDb extends Object {

/**
 * Holds the parsed MagicDb for this class instance
 *
 * @var array
 */
        var $db = array();

/**
 * Reads a MagicDb from various formats
 *
 * @var $magicDb mixed Can be an array containing the db, a magic db as a string, or a filename pointing to a magic db in .db or magic.db.php format
 * @return boolean Returns false if reading / validation failed or true on success.
 * @author        Felix
 */
        function read($magicDb = null) {
                if (!is_string($magicDb) && !is_array($magicDb)) {
                        return false;
                }
                if (is_array($magicDb) || strpos($magicDb, '# FILE_ID DB') === 0) {
                        $data = $magicDb;
                } else {
                        $File =& new File($magicDb);
                        if (!$File->exists()) {
                                return false;
                        }
                        if ($File->ext() == 'php') {
                                include($File->pwd());
                                $data = $magicDb;
                        } else {
                                // @TODO: Needs test coverage
                                $data = $File->read();
                        }
                }

                $magicDb = $this->toArray($data);
                if (!$this->validates($magicDb)) {
                        return false;
                }
                return !!($this->db = $magicDb);
        }

/**
 * Parses a MagicDb $data string into an array or returns the current MagicDb instance as an array
 *
 * @param string $data A MagicDb string to turn into an array
 * @return array A parsed MagicDb array or an empty array if the $data param was invalid. Returns the db property if $data is not set.
 * @access public
 */
        function toArray($data = null) {
                if (is_array($data)) {
                        return $data;
                }
                if ($data === null) {
                        return $this->db;
                }

                if (strpos($data, '# FILE_ID DB') !== 0) {
                        return array();
                }

                $lines = explode("\r\n", $data);
                $db = array();

                $validHeader = count($lines) > 3
                                        && preg_match('/^# Date:([0-9]{4}-[0-9]{2}-[0-9]{2})$/', $lines[1], $date)
                                        && preg_match('/^# Source:(.+)$/', $lines[2], $source)
                                        && strlen($lines[3]) == 0;
                if (!$validHeader) {
                        return $db;
                }

                $db = array('header' => array('Date' => $date[1], 'Source' => $source[1]), 'database' => array());
                $lines = array_splice($lines, 3);

                $format = array();
                while (!empty($lines)) {
                        $line = array_shift($lines);
                        if (isset($line[0]) && $line[0] == '#' || empty($line)) {
                                continue;
                        }

                        $columns = explode("\t", $line);
                        if (in_array($columns[0]{0}, array('>', '&'))) {
                                $format[] = $columns;
                        } elseif (!empty($format)) {
                                $db['database'][] = $format;
                                $format = array($columns);
                        } else {
                                $format = array($columns);
                        }
                }

                return $db;
        }

/**
 * Returns true if the MagicDb instance or the passed $magicDb is valid
 *
 * @param mixed $magicDb A $magicDb string / array to validate (optional)
 * @return boolean True if the $magicDb / instance db validates, false if not
 * @access public
 */
        function validates($magicDb = null) {
                if (is_null($magicDb)) {
                        $magicDb = $this->db;
                } elseif (!is_array($magicDb)) {
                        $magicDb = $this->toArray($magicDb);
                }

                return isset($magicDb['header'], $magicDb['database']) && is_array($magicDb['header']) && is_array($magicDb['database']);
        }

/**
 * Analyzes a given $file using the currently loaded MagicDb information based on the desired $options
 *
 * @param string $file Absolute path to the file to analyze
 * @param array $options TBT
 * @return mixed
 * @access public
 */
        function analyze($file, $options = array()) {
                if (!is_string($file)) {
                        return false;
                }

                $matches = array();
                $MagicFileResource =& new MagicFileResource($file);
                foreach ($this->db['database'] as $format) {
                        $magic = $format[0];
                        $match = $MagicFileResource->test($magic);
                        if ($match === false) {
                                continue;
                        }
                        $matches[] = $magic;
                }

                return $matches;
        }
}

/**
 * undocumented class
 *
 * @package       cake.tests
 * @subpackage    cake.tests.cases.libs
 */
class MagicFileResource extends Object{

/**
 * undocumented variable
 *
 * @var unknown
 * @access public
 */
        var $resource = null;

/**
 * undocumented variable
 *
 * @var unknown
 * @access public
 */
        var $offset = 0;

/**
 * undocumented function
 *
 * @param unknown $file
 * @return void
 * @access public
 */
        function __construct($file) {
                if (file_exists($file)) {
                        $this->resource =& new File($file);
                } else {
                        $this->resource = $file;
                }
        }

/**
 * undocumented function
 *
 * @param unknown $magic
 * @return void
 * @access public
 */
        function test($magic) {
                $offset = null;
                $type = null;
                $expected = null;
                $comment = null;
                if (isset($magic[0])) {
                        $offset = $magic[0];
                }
                if (isset($magic[1])) {
                        $type = $magic[1];
                }
                if (isset($magic[2])) {
                        $expected = $magic[2];
                }
                if (isset($magic[3])) {
                        $comment = $magic[3];
                }
                $val = $this->extract($offset, $type, $expected);
                return $val == $expected;
        }

/**
 * undocumented function
 *
 * @param unknown $type
 * @param unknown $length
 * @return void
 * @access public
 */
        function read($length = null) {
                if (!is_object($this->resource)) {
                        return substr($this->resource, $this->offset, $length);
                }
                return $this->resource->read($length);
        }

/**
 * undocumented function
 *
 * @param unknown $type
 * @param unknown $expected
 * @return void
 * @access public
 */
        function extract($offset, $type, $expected) {
                switch ($type) {
                        case 'string':
                                $this->offset($offset);
                                $val = $this->read(strlen($expected));
                                if ($val === $expected) {
                                        return true;
                                }
                                break;
                }
        }

/**
 * undocumented function
 *
 * @param unknown $offset
 * @param unknown $whence
 * @return void
 * @access public
 */
        function offset($offset = null) {
                if (is_null($offset)) {
                        if (!is_object($this->resource)) {
                                return $this->offset;
                        }
                        return $this->offset;
                }

                if (!ctype_digit($offset)) {
                        return false;
                }
                if (is_object($this->resource)) {
                        $this->resource->offset($offset);
                } else {
                        $this->offset = $offset;
                }
        }
}