高手写的一个php文件上传类，可以检查真实扩展名

<?php // +------------------------------------------------------------------------+ // | class.upload.php | // +------------------------------------------------------------------------+ // | Copyright (c) Colin Verot 2003-2010. All rights reserved. | // | Version 0.30 | // | Last modified 05/09/2010 | // | Email colin@verot.net | // | Web http://www.verot.net | // +------------------------------------------------------------------------+ // | This program is free software; you can redistribute it and/or modify | // | it under the terms of the GNU General Public License version 2 as | // | published by the Free Software Foundation. | // | | // | This program is distributed in the hope that it will be useful, | // | but WITHOUT ANY WARRANTY; without even the implied warranty of | // | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | // | GNU General Public License for more details. | // | | // | You should have received a copy of the GNU General Public License | // | along with this program; if not, write to the | // | Free Software Foundation, Inc., 59 Temple Place, Suite 330, | // | Boston, MA 02111-1307 USA | // | | // | Please give credit on sites that use class.upload and submit changes | // | of the script so other people can use them as well. | // | This script is free to use, don't abuse. | // +------------------------------------------------------------------------+ // /** * Class upload * * @version 0.30 * @author Colin Verot <colin@verot.net> * @license http://opensource.org/licenses/gpl-license.php GNU Public License * @copyright Colin Verot * @package cmf * @subpackage external */ /** * Class upload * * <b>What does it do?</b> * * It manages file uploads for you. In short, it manages the uploaded file, * and allows you to do whatever you want with the file, especially if it * is an image, and as many times as you want. * * It is the ideal class to quickly integrate file upload in your site. * If the file is an image, you can convert, resize, crop it in many ways. * You can also apply filters, add borders, text, watermarks, etc... * That's all you need for a gallery script for instance. Supported formats * are PNG, JPG, GIF and BMP. * * You can also use the class to work on local files, which is especially * useful to use the image manipulation features. The class also supports * Flash uploaders. * * The class works with PHP 4 and 5, and its error messages can * be localized at will. * * <b>How does it work?</b> * * You instanciate the class with the $_FILES['my_field'] array * where my_field is the field name from your upload form. * The class will check if the original file has been uploaded * to its temporary location (alternatively, you can instanciate * the class with a local filename). * * You can then set a number of processing variables to act on the file. * For instance, you can rename the file, and if it is an image, * convert and resize it in many ways. * You can also set what will the class do if the file already exists. * * Then you call the function {@link process} to actually perform the actions * according to the processing parameters you set above. * It will create new instances of the original file, * so the original file remains the same between each process. * The file will be manipulated, and copied to the given location. * The processing variables will be reset once it is done. * * You can repeat setting up a new set of processing variables, * and calling {@link process} again as many times as you want. * When you have finished, you can call {@link clean} to delete * the original uploaded file. * * If you don't set any processing parameters and call {@link process} * just after instanciating the class. The uploaded file will be simply * copied to the given location without any alteration or checks. * * Don't forget to add <i>enctype="multipart/form-data"</i> in your form * tag <form> if you want your form to upload the file. * * <b>How to use it?</b><br> * Create a simple HTML file, with a form such as: * <pre> * <form enctype="multipart/form-data" method="post" action="upload.php"> * <input type="file" size="32" name="image_field" value=""> * <input type="submit" name="Submit" value="upload"> * </form> * </pre> * Create a file called upload.php: * <pre> * $handle = new upload($_FILES['image_field']); * if ($handle->uploaded) { * $handle->file_new_name_body = 'image_resized'; * $handle->image_resize = true; * $handle->image_x = 100; * $handle->image_ratio_y = true; * $handle->process('/home/user/files/'); * if ($handle->processed) { * echo 'image resized'; * $handle->clean(); * } else { * echo 'error : ' . $handle->error; * } * } * </pre> * * <b>How to process local files?</b><br> * Use the class as following, the rest being the same as above: * <pre> * $handle = new upload('/home/user/myfile.jpg'); * </pre> * * <b>How to set the language?</b><br> * Instantiate the class with a second argument being the language code: * <pre> * $handle = new upload($_FILES['image_field'], 'fr_FR'); * $handle = new upload('/home/user/myfile.jpg', 'fr_FR'); * </pre> * * <b>How to output the resulting file or picture directly to the browser?</b><br> * Simply call {@link process}() without an argument (or with null as first argument): * <pre> * $handle = new upload($_FILES['image_field']); * header('Content-type: ' . $handle->file_src_mime); * echo $handle->Process(); * die(); * </pre> * Or if you want to force the download of the file: * <pre> * $handle = new upload($_FILES['image_field']); * header('Content-type: ' . $handle->file_src_mime); * header("Content-Disposition: attachment; filename=".rawurlencode($handle->file_src_name).";"); * echo $handle->Process(); * die(); * </pre> * * <b>Processing parameters</b> (reset after each process) * <ul> * <li><b>{@link file_new_name_body}</b> replaces the name body (default: '')<br> * <pre>$handle->file_new_name_body = 'new name';</pre></li> * <li><b>{@link file_name_body_add}</b> appends to the name body (default: '')<br> * <pre>$handle->file_name_body_add = '_uploaded';</pre></li> * <li><b>{@link file_name_body_pre}</b> prepends to the name body (default: '')<br> * <pre>$handle->file_name_body_pre = 'thumb_';</pre></li> * <li><b>{@link file_new_name_ext}</b> replaces the file extension (default: '')<br> * <pre>$handle->file_new_name_ext = 'txt';</pre></li> * <li><b>{@link file_safe_name}</b> formats the filename (spaces changed to _) (default: true)<br> * <pre>$handle->file_safe_name = true;</pre></li> * <li><b>{@link file_overwrite}</b> sets behaviour if file already exists (default: false)<br> * <pre>$handle->file_overwrite = true;</pre></li> * <li><b>{@link file_auto_rename}</b> automatically renames file if it already exists (default: true)<br> * <pre>$handle->file_auto_rename = true;</pre></li> * <li><b>{@link dir_auto_create}</b> automatically creates destination directory if missing (default: true)<br> * <pre>$handle->auto_create_dir = true;</pre></li> * <li><b>{@link dir_auto_chmod}</b> automatically attem