[php] How to check whether the user uploaded a file in PHP?

@karim79 has the right answer, but I had to rewrite his example to suit my purposes. His example assumes that the name of the submitted field is known and can be hard coded in. I took that a step further and made a function that will tell me if any files were uploaded without having to know the name of the upload field.

/**
 * Tests all upload fields to determine whether any files were submitted.
 * 
 * @return boolean
 */
function files_uploaded() {

    // bail if there were no upload forms
   if(empty($_FILES))
        return false;

    // check for uploaded files
    $files = $_FILES['files']['tmp_name'];
    foreach( $files as $field_title => $temp_name ){
        if( !empty($temp_name) && is_uploaded_file( $temp_name )){
            // found one!
            return true;
        }
    }   
    // return false if no files were found
   return false;
}