Resumable downloads with VB

Is it possible to create a VB app that will resume internet downloads like Getright, Go!Zilla, FlashGet, etc?

I use VB6 Pro.

Thanks in advance
John Barker
Johnb@the_pub.co.uk

[privoli]

Yes it is possible to do so but you will need to know...

a). How big the file is
b). How much of the file you already ave
c). Does the server support resuming?

A). You can find that out by doing a HTTP request header via the server, simply connect to the HTTPd server and ask for the file header, it will tell you, its type, size, date, time and if you can have it or not

B). You can get this by simply doing a calc on the size of the file on the hard disk

C). The only way you will find out if the server supports resuming or not is by doing asking for the HTTPd to resume a file, it if says yes and starts sending, it supports it, if it says error and starts from 0 bytes then it doesnt support.

Most FTP clients when they are connecting do something like..

Client> REST 100
Server> 200 Rest command okay. Resuming at byte offset 100
Client> *** This site can resume broken downloads

In a case where you have a server that doesn't support resuming you will get....

Client> REST 100
Server> 500 Command not implemented
Client> *** This site CANNOT resume broken downloads

REST means, restore download at x bytes.
If you have 1.4mb of a file and want to resume it you would do

REST 1456103

but thats for an FTP server and not a HTTPd server.

If you are serious about making this look up some HTTP and FTP RFC Documents and look for resuming downloads for the exact commands and syntax