How to get file size from Amazon AWS S3 Version 2?

Question

I am forced to use Version 2 of AWS S3, because i cannot update PHP to 5.5 on this server in order to use Version 3.

I made this PHP script to download files from AWS, which works good:

//http://docs.aws.amazon.com/aws-sdk-php/v2/api/class-Aws.S3.S3Client.html#_createPresignedUrl
// Get a command object from the client and pass in any options
// available in the GetObject command (e.g. ResponseContentDisposition)
$command = $s3Client->getCommand('GetObject', array(
    'Bucket' => $bucket,
    'Key' => $objectKey,
    'ResponseContentDisposition' => 'attachment; filename="' . $originFilename . '"'
));

// Create a signed URL from the command object that will last for
// 10 minutes from the current time
$signedUrl = $command->createPresignedUrl('+1000 minutes');

$file = file_get_contents($signedUrl);

The problem is that i want to be sure that the file_get_contents() downloads the entire file and to detect and fix any error (like server going offline during a download, etc...), so i thought the following flow:

1. I ask AWS the file size
2. I download the file
3. I check the size. If it's not equal i re-download the file

So, how to get file size from AWS? I found this, but it doesn't work for my version.

Answer 1

You can use the HEAD Object REST API to determine the size of the object stored on S3.

HEAD Object will return the meta-data associated with the stored S3 Object, including the size on disk of the object, within the Content-Length header.

http://docs.aws.amazon.com/aws-sdk-php/v2/api/class-Aws.S3.S3Client.html#_headObject