require("aws.phar");
use AwsS3S3Client;
use AwsS3ExceptionS3Exception;

$bucket = 'my bucket';
$filepath = 'currentfilepath.jpeg';
$filename = 'newfilename.jpeg';

$s3 = S3Client::factory(array(
    'key'    => 'XXX',
    'secret' => 'YYY',
    'region'  => 'eu-west-2',
    'version' => 'latest'
));

try {
   $result = $s3->putObject(array(
        'Bucket' => $bucket,
        'Key'    => $filename,
        'SourceFile'   => $filepath,
        'ACL'    => 'public-read'
         ));
  var_dump($result);
} catch (S3Exception $e) {
    echo $e->getMessage() . "n";
}