From 793eb160822860ebc78777f4397c224c06d1f0d4 Mon Sep 17 00:00:00 2001
From: svollbehr <svollbehr@51a70ab9-7547-0410-9469-37e369ee0574>
Date: Sat, 12 Apr 2008 19:07:31 +0000
Subject: [PATCH] Add support to Mime Magic

git-svn-id: http://php-reader.googlecode.com/svn/trunk@73 51a70ab9-7547-0410-9469-37e369ee0574
---
 src/Magic.php | 177 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 177 insertions(+)
 create mode 100644 src/Magic.php

diff --git a/src/Magic.php b/src/Magic.php
new file mode 100644
index 0000000..21a3c27
--- /dev/null
+++ b/src/Magic.php
@@ -0,0 +1,177 @@
+<?php
+/**
+ * PHP Reader Library
+ *
+ * Copyright (c) 2006-2008 The PHP Reader Project Workgroup. All rights
+ * reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *  - Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *  - Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *  - Neither the name of the project workgroup nor the names of its
+ *    contributors may be used to endorse or promote products derived from this
+ *    software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * @package   php-reader
+ * @copyright Copyright (c) 2006-2008 PHP Reader Project Workgroup
+ * @license   http://code.google.com/p/php-reader/wiki/License New BSD License
+ * @version   $Id$
+ */
+
+/**#@+ @ignore */
+require_once("Reader.php");
+/**#@-*/
+
+/**
+ * This class is used to classify the given file using some magic bytes
+ * characteristic to a particular file type. The classification information can
+ * be a MIME type or just text describing the file.
+ *
+ * This method is slower than determining the type by file suffix but on the
+ * other hand reduces the risk of fail positives during the test.
+ *
+ * The magic file consists of ASCII characters defining the magic numbers for
+ * different file types. Each row has 4 to 5 columns, empty and commented lines
+ * (those starting with a hash character) are ignored. Columns are described
+ * below.
+ *
+ *  o <b>1</b> -- byte number to begin checking from. ">" indicates a dependency
+ *    upon the previous non-">" line
+ *  o <b>2</b> -- type of data to match. Can be one of following
+ *    - <i>byte</i> (single character)
+ *    - <i>short</i> (machine-order 16-bit integer)
+ *    - <i>long</i> (machine-order 32-bit integer)
+ *    - <i>string</i> (arbitrary-length string)
+ *    - <i>date</i> (long integer date (seconds since Unix epoch/1970))
+ *    - <i>beshort</i> (big-endian 16-bit integer)
+ *    - <i>belong</i> (big-endian 32-bit integer)
+ *    - <i>bedate</i> (big-endian 32-bit integer date)
+ *    - <i>leshort</i> (little-endian 16-bit integer)
+ *    - <i>lelong</i> (little-endian 32-bit integer)
+ *    - <i>ledate</i> (little-endian 32-bit integer date)
+ *  o <b>3</b> -- contents of data to match
+ *  o <b>4</b> -- file description/MIME type if matched
+ *  o <b>5</b> -- optional MIME encoding if matched and if above was a MIME type
+ *
+ * @package   php-reader
+ * @author    Sven Vollbehr <svollbehr@gmail.com>
+ * @copyright Copyright (c) 2006-2008 PHP Reader Project Workgroup
+ * @license   http://code.google.com/p/php-reader/wiki/License New BSD License
+ * @version   $Rev$
+ */
+final class Magic
+{
+  /** @var string */
+  private $_magic;
+  
+  /**
+   * Reads the magic information from given magic file.
+   *
+   * @param string $filename The path to the magic file.
+   */
+  public function __construct($filename)
+  {
+    $reader = new Reader($filename);
+    $this->_magic = $reader->read($reader->getSize());
+  }
+  
+  /**
+   * Returns the recognized MIME type/description of the given file. The type
+   * is determined by the content using magic bytes characteristic for the
+   * particular file type.
+   *
+   * If the type could not be found, the function returns the default value, or
+   * <var>false</var>.
+   *
+   * @param string $filename The file path whose type to determine.
+   * @param string $default  The default value.
+   * @return string|false
+   */
+  public function getType($filename, $default = false)
+  {
+    $reader = new Reader($filename);
+
+    $parentOffset = 0;
+    foreach (preg_split("/^/m", $this->_magic) as $line) {
+      $chunks = array();
+      if (!preg_match("/^(?P<Dependant>>?)(?P<Byte>\d+)\s+(?P<MatchType>\S+)" .
+                      "\s+(?P<MatchData>\S+)(?:\s+(?P<MIMEType>[a-z]+\/[a-z-" .
+                      "0-9]+)?(?:\s+(?P<Description>.+))?)?$/", $line, $chunks))
+        continue;
+      
+      if ($chunks["Dependant"]) {
+        $reader->setOffset($parentOffset);
+        $reader->skip($chunks["Byte"]);
+      } else
+        $reader->setOffset($parentOffset = $chunks["Byte"]);
+
+      $matchType = strtolower($chunks["MatchType"]);
+      $matchData = preg_replace
+        (array("/\\\\ /", "/\\\\\\\\/", "/\\\\([0-7]{1,3})/e",
+               "/\\\\x([0-9A-Fa-f]{1,2})/e", "/0x([0-9A-Fa-f]+)/e"),
+         array(" ", "\\\\", "pack(\"H*\", base_convert(\"$1\", 8, 16));",
+               "pack(\"H*\", \"$1\");", "hexdec(\"$1\");"),
+         $chunks["MatchData"]);
+
+      switch ($matchType) {
+      case "byte":    // single character
+        $data = $reader->readInt8();
+        break;
+      case "short":   // machine-order 16-bit integer
+        $data = $reader->readInt16();
+        break;
+      case "long":    // machine-order 32-bit integer
+        $data = $reader->readInt32();
+        break;
+      case "string":  // arbitrary-length string
+        $data = $reader->readString8(strlen($matchData));
+        break;
+      case "date":    // long integer date (seconds since Unix epoch/1970)
+        $data = $reader->readInt64BE();
+        break;
+      case "beshort": // big-endian 16-bit integer
+        $data = $reader->readUInt16BE();
+        break;
+      case "belong":  // big-endian 32-bit integer
+      case "bedate":  // big-endian 32-bit integer date
+        $data = $reader->readUInt32BE();
+        break;
+      case "leshort": // little-endian 16-bit integer
+        $data = $reader->readUInt16LE();
+        break;
+      case "lelong":  // little-endian 32-bit integer
+      case "ledate":  // little-endian 32-bit integer date
+        $data = $reader->readUInt32LE();
+        break;
+      default:
+        $data = null;
+        break;
+      }
+
+      if (strcmp($data, $matchData) == 0) {
+        if (!empty($chunks["MIMEType"]))
+          return $chunks["MIMEType"];
+        if (!empty($chunks["Description"]))
+          return $chunks["Description"];
+      }
+    }
+    return $default;
+  }
+}