Adding Valid File Types - PHP form

Question

I am trying to add accepted file types to a form that was built by someone else. I'm not exactly proficient with PHP.

Can anyone indicate where I am going wrong? I have tried replicating part of the form by adding RTF and TXT file types however the form doesn't appear to accept them still.

Any help is greatly appreciated.

if($_FILES['file']['error'] == UPLOAD_ERR_OK) {

    $finfo = finfo_open(FILEINFO_MIME_TYPE);
    $mime = finfo_file($finfo, $_FILES['file']['tmp_name']);

    if($mime == 'application/msword' || $mime == 'application/pdf' || $mime == 'application/rtf' || $mime == 'text/plain'){

        //Check 'temp' Directory Exsists
        if(!file_exists(WP_CONTENT_DIR .'/uploads/temp')){
            mkdir(WP_CONTENT_DIR .'/uploads/temp', 0777, true);
        }
        move_uploaded_file($_FILES["file"]["tmp_name"], WP_CONTENT_DIR .'/uploads/temp/'.basename($_FILES['file']['name']));
        $attachment = array(WP_CONTENT_DIR ."/uploads/temp/".$_FILES["file"]["name"]);
    } else {
        $validation_message = "<span class='error'><i class='icon-remove-sign'></i> Invalid File Type</span>";
        $attachment = NULL;
        $passes = false;
    }

    } else {
        $attachment = NULL;
    }

Answer 1

You may check by getting the output of variable $mime. You can also put the type in superglobal array $_FILES.

$mime = finfo_file($finfo, $_FILES['file']['type']);