如何在PHP中限制文件上传大小？

Question

I want to save bandwidth and restrict the size of uploaded files to our webpage. The problem is that I can set the maximal size of uploaded file (eg, 1 MB) but a user can select 50 MB file and can upload it to find out that PHP really doesn't accept files of this size -- the uploading is totally unnecessary.

Can I prevent this somehow?

(I can check file size in Javascript but not all browsers support this. Flash is an option but it's not universal either).

Thanks!

Answer 1

Use the LimitRequestBody Directive in .htaccess :

Example (setting a 1Mb limit). Create/modify your .htaccess file (in your webroot, or higher), and add:

LimitRequestBody 1048576

When the limit is exceeded, the request will be interrupted . The user will get a response similar to:

413 Request entity too large

---

Also: Rule 1: Never trust the client! You should always do such checks server-side, because the client can easily circumvent your JavaScript checks, and do anything which is not restricted by the server.