php - 重命名上传的文件以避免覆盖

Question

我有这个简单的脚本，它工作正常，但目前会覆盖具有重复名称的文件。我怎样才能避免这种情况？

<?php
   // Configuration - Your Options
    $allowed_filetypes = array('.mp3'); // These will be the types of file that will pass the validation.
    $max_filesize = 1048576; // Maximum filesize in BYTES (currently 0.5MB).
    $upload_path = './uploads/'; // The place the files will be uploaded to (currently a 'files' directory).

    $filename = $_FILES['userfile']['name']; // Get the name of the file (including file extension).
    $ext = substr($filename, strpos($filename,'.'), strlen($filename)-1); // Get the extension from the filename.

    if(!in_array($ext,$allowed_filetypes))

        header('Location: http://www.website.com/five/error');

    if(filesize($_FILES['userfile']['tmp_name']) > $max_filesize)

        header('Location: http://www.website.com/five/error');

    if(!is_writable($upload_path))

        header('Location: http://www.website.com/five/error');

    if(move_uploaded_file($_FILES['userfile']['tmp_name'],$upload_path . $filename))

//         echo 'Your file upload was successful, view the file <a href="' . $upload_path . $filename . '" title="Your File">here</a>'; // It worked.
        header('Location: http://www.website.com/five/sent');

    else

        header('Location: http://www.website.com/five/error');

?>

Answer 1

添加 if (file_exists($upload_path.$filename))上传前，设置 $filename如果有的话。