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Attaching $fields to $_FILES

If I have the following associative array:

$fields = [ //store empty fields 'name' => $_POST['name'], 'email' => $_POST['email'],
'phone' => $_POST['phone'], 'location' => $_POST['location'], 'proposal' => $_POST['proposal'] //--------------> proposal = attachment file ]; How do I use them for $_FILES["attachment"]["name"] ?

My plan is to check whether the proposal is pdf, docx, or .doc

here is what I did so far:

    if(!empty($_FILES[$fields['proposal']]['name']) ){
        $fileName = $_FILES[$fields['proposal']]['name'];
        $tempName = $_FILES[$fields['proposal']]['tmp_name'];
        $fileType = $_FILES[$fields['proposal']]['type'];

        //get the extension of the file
        $base = basename($fileName);
        $extension = substr($base, strlen($base)-4, strlen($base));

        //only these file types will be allowed
        $allowedExtension = array(".doc", ".pdf", "docx");

        //check that this file type is allowed
        if (in_array($extension, $allowedExtension)) {

        }else {
        $errors['proposal'] = 'You can only upload pdf files';                  


1 Answer

Hey Roger,

Don't ever trust the extension to be true - a jpg could have an extension of "gif", for example. Instead, look at the MIME content-type (and don't trust the one provided in $_FILES, either).

Ideally, you'll also want to rename a file. Consider if someone uses the same name as a file already existing on your system, and you didn't check if a file exists before uploading. Also, and more nefariously, if you don't take every precaution and a user uploads a script to your site, they can then potentially use this to gain a backdoor into your site.

Here's a good write-up on some of the security involved in allowing users to securely upload files: https://paragonie.com/blog/2015/10/how-securely-allow-users-upload-files

To answer your question though, $_FILES["attachment"]["name"] is the original name of the file on the client machine. You can't use 'name' => $_POST['name'] to change this. The renaming (what the file would be called when it's uploaded) would be done in move_uploaded_file.