If your just looking to run a command and get a copy of a web site, use the tools that others have suggested, such as wget, curl, or some of the GUI tools. I use my own personal tool that I call webreaper (that’s not the Windows WebReaper though. There are a few Perl programs I know about, including webmirror and a few others you can find on CPAN.
If you’re looking to do this inside a Perl program you are writing (since you have the “perl” tag on your answer), there are many tools in CPAN that can help you at each step:
- Downloading content: LWP::Simple, LWP::UserAgent, WWW::Mechanize
- Link extraction: HTML::LinkExtor, HTML::SimpleLinkExtor
- Link rewriting: HTML::Parser
Good luck, 🙂