Sslurp!

Frequently Asked Questions

1.

I've set up Sslurp! to only follow "downward" links. But when I start with a URL like http://server/abc/def, Sslurp also follows links to http://server/abc/xyz/.... Isn't this wrong?

No. Sslurp can't know that def is a "directory". Only the server knows this and sends a default document when def is requested. For Sslurp it looks like def is the document and /abc/ is the "directory". You have to give Sslurp! a hint by adding a trailing /, i.e. start with http://server/abc/def/.

2.

A Java applet that I've downloaded with Sslurp! requires another applet to run, but Sslurp doesn't download that. Why?

Sslurp is not a Java interpreter, so unless the second applet is also referenced in the HTML page, Sslurp doesn't know of it.

3.

I've instructed Sslurp! to download modified items only. But Sslurp! still requests all items (but doesn't download them), slowing down the whole procedure.

Sslurp! doesn't know whether an item is modified or not unless it queries the server. So communication with the server is required either way!

4.

I've instructed Sslurp! to download modified items only. But some items are always downloaded, even when their contents haven't changed.

Not Sslurp! but the server decides if an item is modified or not. When queried, it replies with either "item has not changed, use your local copy" or "item has changed, here it is". When a server sends the item even when the contents hasn't changed, some of the following reasons may apply:

  • The server is buggy, e.g. it doesn't understand the timestamp format that it generated when it sent the initial copy. This is a rare case.
  • The server didn't send a timestamp when sending the initial copy.
  • The item doesn't exist as such, e.g. when it's created dynamically, possibly as database query result. Then there is no date of last modification that the server can send (or it ignores conditional queries for such items).