How to copy multiple files from server to local hard disk in one http request using C++?

Question

How do you copy a group of files from server machine to local hard disk through a C++ web application in one request? This is kind of downloading bulk files to your local machine from a server. I guess in Java you could do this through ZipInputStream and GZipInputStream.

Is it possible to achieve this entirely through server side code? Or will it require a client running on the local machine to carry out the bulk copying of files?

Answer 1

If the user if aware of this, and the files are not nessesary for website rendering, you can push them into an archive and have a link from your site (or do something like sourceforge, redirect to the archive and the browser simply downloads it. For archiving you can use zlib. Just send Content-type as gzip and push data (here from stdin)

int ret;

/* avoid end-of-line conversions */
SET_BINARY_MODE(stdin);
SET_BINARY_MODE(stdout);

ret = def(stdin, stdout, Z_DEFAULT_COMPRESSION);
if (ret != Z_OK)
    zerr(ret);
return ret;

If you are trying to have the whole page (HTML, CSS, JS, IMG) sent as one, all of those files can be inserted into HTML, even images. (see this).

Answer 2

Say you have a Java servlet / ISAPI extension that accepts requests of the form

http://server:port/fileserver?f=FILE1&f=FILE2&.....&f=FILEN

On receipt of such a request, the server side code can, using zlib, pack all the files into a zip file and send the zip file as the HTTP response setting the Content-Type, Content-Length, Last-Modified,etc.

Further Note: If you are using ISAPI on IIS6 and above, you can also add this content into the IIS's kernel mode response cache.