PHP error handling in file upload

Question

I want to put out an error message when the uploaded image size is over 3MB. This is my current code. It puts out an error message properly when an image is over 3MB, but it also puts out an error message when no image is uploaded. How do I fix this?

//image check start
if ((($_FILES["file"]["type"] == "image/gif")
|| ($_FILES["file"]["type"] == "image/jpeg")
|| ($_FILES["file"]["type"] == "image/png")
|| ($_FILES["file"]["type"] == "image/pjpeg"))
&& ($_FILES["file"]["size"] < 3072000))
//image check end
{
    if($_FILES['file']['size'] > 0)
    {
        file uploading script
    } else {
        do nothing
    }
} else {
    error("Maximum image size exceeded or invalid file format.");
}

First of all, you should check if the file is uploaded, and then check for file size and image type. Good luck! — Firula
– Firula, Commented Jun 12, 2012 at 1:58

Izhaki · Accepted Answer · 2012-06-12 01:58:57Z

1

Well, if you consider your condition when no file is uploaded you'll see that it will fail because none of your type checks will return true, and so it'll land on the error line after the final else.

You'd need something like this:

if ( $_FILES['file']['size'] == 0 ) 
{
    // do nothing
} else {
    //image check start
    if ((($_FILES["file"]["type"] == "image/gif")
    || ($_FILES["file"]["type"] == "image/jpeg")
    || ($_FILES["file"]["type"] == "image/png")
    || ($_FILES["file"]["type"] == "image/pjpeg"))
    && ($_FILES["file"]["size"] < 3072000))
    //image check end
    {
        file uploading script
    } else {
        error("Maximum image size exceeded or invalid file format.");
    }
}

Obviously, if you really need to do nothing if no file is uploaded this will do:

if ( $_FILES['file']['size'] != 0 ) 
{
    //image check start
    if ((($_FILES["file"]["type"] == "image/gif")
    || ($_FILES["file"]["type"] == "image/jpeg")
    || ($_FILES["file"]["type"] == "image/png")
    || ($_FILES["file"]["type"] == "image/pjpeg"))
    && ($_FILES["file"]["size"] < 3072000))
    //image check end
    {
        file uploading script
    } else {
        error("Maximum image size exceeded or invalid file format.");
    }
}

answered Jun 12, 2012 at 1:58

Izhaki

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1 Comment

gyogyo0101 Over a year ago

It's still not working but I marked your answered as accepted because now I'm using your second code. Thanks.

Mike · Accepted Answer · 2012-06-12 02:12:04Z

First, you should always enable error reporting in your scripts while debugging. You can do this by

error_reporting(E_ALL);
ini_set("display_errors", 1);

If you are unsure where your error is coming from, you can always try doing print_r($_FILES); and just go through the logic as you have it above. Check the $_FILES['file']['error'] variable for file upload errors. If the upload was successful it will have a value of 0.

if ($_FILES["file"]["error"] !== 0) {
    if ($_FILES["file"]["size"]) > 0) {
        if ((($_FILES["file"]["type"] == "image/gif")
        || ($_FILES["file"]["type"] == "image/jpeg")
        || ($_FILES["file"]["type"] == "image/png")
        || ($_FILES["file"]["type"] == "image/pjpeg"))
        && ($_FILES["file"]["size"] < 3072000))
        //image check end
        {
            if($_FILES['file']['size'] > 0) {
                // file uploading script
            } 
            else {
                // do nothing
            }
        }
        else {
            error("Maximum image size exceeded or invalid file format.");
        }
    }
    else {
        error("Error uploading file. File has size of 0 bytes");
    }
}
else {
    error("There was an error uploading the file.
        File upload returned error code: " . $_FILES["file"]["error"]
    );
}

gyogyo0101 · Accepted Answer · 2012-06-20 07:51:53Z

0

The problem was

upload_max_filesize = 3M

in my php.ini file. When I changed it to

upload_max_filesize = 4M

Everything worked just fine.

Thanks.

answered Jun 20, 2012 at 7:51

gyogyo0101

611 gold badge2 silver badges10 bronze badges

1 Comment

DaveWalley Over a year ago

This is NOT the answer to your original question at all, and you should not be giving yourself credit. Yes, your real problem may have gone away, but others have spent time and effort answering what you actually asked, and they deserve some token respect even if you no longer care.

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