I don't know that this is specifically a PHP question, but I've tried
searching for leads and am now going to ask here.

I am developing a PHP application that allows users to manage projects
and to upload and search documents related to the projects they are
managing. One type of document they may want to reference is an
external web page. If I want to allow the user to copy a URL into a
form field and then use that to go out and archive a local copy of the
destination page as it exists, how would I do that?

Thanks,
Mike