php文件上传 覆盖上传
I create a lot of websites that allow administrators to upload files to their own website. Since allowing user customization has become more and more important on websites these days, I thought I'd share how easy it is to handle file uploads in PHP.
我创建了许多网站，允许管理员将文件上传到自己的网站。 由于近来允许用户自定义在网站上变得越来越重要，所以我想分享一下使用PHP处理文件上传的难易程度。
XHTML表单 (The XHTML Form)
You'll need to use the multipart/form-data value for the form's enctype property. You'll also obviously need at least one input element of the file type. The form's action tag must provide a URL which points the a file containing the piece of PHP below.
您需要将multipart / form-data值用于表单的enctype属性。 显然，您还至少需要一个文件类型的输入元素。 表单的动作标签必须提供一个URL，该URL指向一个包含下面PHP片段的文件。
PHP (The PHP)
//if they DID upload a file...if($_FILES['photo']['name']){ //if no errors... if(!$_FILES['photo']['error']) { //now is the time to modify the future file name and validate the file $new_file_name = strtolower($_FILES['photo']['tmp_name']); //rename file if($_FILES['photo']['size'] > (1024000)) //can't be larger than 1 MB { $valid_file = false; $message = 'Oops! Your file\'s size is to large.'; } //if the file has passed the test if($valid_file) { //move it to where we want it to be move_uploaded_file($_FILES['photo']['tmp_name'], 'uploads/'.$new_file_name); $message = 'Congratulations! Your file was accepted.'; } } //if there is an error... else { //set that to be the returned message $message = 'Ooops! Your upload triggered the following error: '.$_FILES['photo']['error']; }}//you get the following information for each file:$_FILES['field_name']['name']$_FILES['field_name']['size']$_FILES['field_name']['type']$_FILES['field_name']['tmp_name'] My commenting in the PHP above outlines the way the process works, so I'll just mention a few notes about file uploads in PHP:
我在上面PHP中的评论概述了该过程的工作方式，因此，我仅提及有关PHP中文件上传的一些注意事项：
- Many shared hosting servers allow a very low maximum file upload size. If you plan on accepting larger files, you should consider a dedicated or virtual dedicated server. 许多共享的托管服务器允许非常小的最大文件上传大小。 如果计划接受较大的文件，则应考虑使用专用服务器或虚拟专用服务器。
To adjust the file upload size in PHP, modify the php.ini file's "upload_max_filesize" value. You can also adjust this value using PHP's .ini_set() function.
要在PHP中调整文件上传大小，请修改php.ini文件的“ upload_max_filesize”值。 您还可以使用PHP的.ini_set()函数来调整此值。
The file upload counts towards the hosting environment's $_POST size, so you may need to increase the php.ini file's post_max_size value.
文件上载将计入托管环境的$ _POST大小，因此您可能需要增加php.ini文件的post_max_size值。
Be sure to do a lot of file validation when allowing users to upload files. How horrible would it be to allow a user to upload a .exe file to your server? They could do horrible things on the server.
允许用户上传文件时，请确保进行大量文件验证。 允许用户将.exe文件上传到您的服务器有多可怕？ 他们可能在服务器上做可怕的事情。
翻译自:
php文件上传 覆盖上传