The S3.php file is taken from https://github.com/tpyo/amazon-s3-php-class .
No need to download sdk.
In the upload.php file you will get the code to upload any file to amazon S3 using simple PHP code.
In the getFiles.php you will get the code to fetch all the files from your bucket.
In the config.php file you have to set your credentials.
For any query mail me at gourav@codewithbogo.in