my $sftp = Net::SFTP::Foreign->new(host =>$host, user => $user, key_path => [$privkey, $pubkey] , more => '-v');

[... debug output ...]
Transferred: sent 32700048, received 60544 bytes, in 1.6 seconds
Bytes per second: sent 20997978.1, received 38877.7
[... more debug output ..]

##</code><code>##

my $BYTES = 0;

$sftp->put(               
    "testfile",           
    "testfile",           
    cleanup  => 1,        
    callback => sub {        
                          
        my ( $sftp, $data, $offset, $size ) = @_; 
        print $offset ." of ". $size ." bytes copied\n";
last_bytes($offset);                                                            
    } );     

print "\nTransferred $BYTES bytes\n";
                                                                                      
sub last_bytes {
    my ($bytes) = @_;
    $BYTES = $bytes;
} 


##</code><code>##

$curl->getinfo( CURLINFO_SIZE_UPLOAD );