Limiting upload size successfully?

_Si_

Hello all, my first post here, shame it has to be a cry for help.

I'm trying to get file uploads working on a new site I'm developing, and everything is fine except for uploading large files.

I've tried searching for help, but they all come at the problem from the other end, see I don't want the users to upload anything over 4meg.

I've put in MAX_FILE_SIZE at 4194304 in the form, then in the script which processes results I check the $_FILES['file']['error'] variable. If it's set to 1 or 2 I report a file size upload error.

Otherwise I try and move it out of the temporary folder and check the filesize() results and again report an error if due.

When I run the script, if I upload a large file in Firefox 3, it hangs for a few minutes then returns me the appropriate error file size error. However if I do the same in IE7 or 8 it hangs for a long time (a few minutes), then just gives me page cannot be displayed.

It's probably just a hole in my understanding. I presumed browsers would check the MAX_FILE_SIZE variable in the first instance and not even bother uploading the first 4 meg of a file only to tell the user it's too big?

I'm just completely flumoxed as to why I get a page cannot be displayed. It's like the script is timing out before it realises that say a 7meg file is larger than the 4meg limit. I can't believe though to limit an upload I need to increase execution time of a script. It seems completely counter intuitive to me.

Is there a way I can make this happen sooner without having to resort to an applet or something to check it client side?

We're running PHP 5.1.5 under IIS on Win NT, and as I say testing with FF3 and IE7/8.

I can provide code samples if it will help, but I strongly suspect someone will point out my stupid error before that point 😉

Thanks for any help you can offer,
Si

bradgrafelman

_Si_ wrote:
It's probably just a hole in my understanding. I presumed browsers would check the MAX_FILE_SIZE variable in the first instance and not even bother uploading the first 4 meg of a file only to tell the user it's too big?

Good thing you presumed instead of assumed, because we all know what they say about that... 🙂

Your presumption was wrong; I have yet to come across a browser that actually supports this feature. It would be nice, and obviously the PHP developers wanted it to happen, but no standard adopted it nor was it ever looked into as a proprietary method for any popular browsers that I can think of. Besides, even if it was part of a standard, what makes you think Micro$oft would take any notice? :p

_Si_ wrote:
However if I do the same in IE7 or 8 it hangs for a long time (a few minutes), then just gives me page cannot be displayed.

At the very bottom of that page, does it give you an HTTP status code in small text, i.e. "HTTP 500 - Internal Server Error" or something of the like?

IE by default will hide such status code pages returned from webservers and instead display the built-in "Page Cannot Be Displayed" page instead. I like to call it the "pretty, boring and utterly useless page." Try disabling this "feature" to see if you get any more information. I'm not sure how to do it in IE7 or 8 (having never used either), but in IE6 it used to be an Advanced setting called "Show friendly HTTP error messages."