🚀 go-pugleaf

"ScOe" <sven.savic@zg.hinet.hr> wrote in message
news:3f318f93@newsgroups.borland.com...

> I have encounter too many times, after downloading
> 15MB and more that downloaded file is corrupted ...

The only way that can happen is either 1) when you are already downloading
pieces of the file and did not synch them up correctly, 2) the file is
already corrupt on the server, or 3) your HD is corrupted.

Please show your actual code that is corrupting files.

> now i want to make a download manager that will synch
> my file on drive and that on the FTP server or so, and
> download only those corrupted bits, bytes or megabytes.

FTP does not support downloading pieces of files.  You can start the
download at a particular offset, but the download will progress to the end
of the file regardless.

You have no way of knowing which bytes are corrupted unless you do a
byte-for-byte comparison of both files in full, in which case you have to
download the server's file entirely any way so you may as well just
re-download it in full each time.

Your only hope that I can think of right now is if you are writing your own
FTP server and client, in which case you can implement your own custom SITE
commands.  You could implement such a command that performs a CRC check on
the client's file, then request a CRC check of the server's file, then
compare the results, and if needed then implement another custom SITE
command that transfers only pieces of the file.

Of course, implementing custom commands means that your stuff will not work
with other third-party clients/servers at all, unless they are updated to
support your commands (good luck on that).


Gambit