Lets say that I want to recursively download all of today's posts on stackexchange as well as any wikipedia articles that they link to.  wget -kprcH -l 4 -t 3 stackexchange.comis not a good option, as it will go to a lot of other foreign sites other than wikipedia and stackexchange. If I use wget -kprcH -l 4 -t 3 -D *stackexchange.com,*overflow.com,*overflow.net,*wikipedia.org stackexchange.comI end up downloading one and only one page, stackexchange.com What command should I use to download all of today's stackexchange and any wikipedia links that it might include without downloading a large amount of unwanted materials? 
Download all of today's stackexchange with wget
wget
Remove the * (asterisk) in front of the sites.  I tried this and it downloaded stackexchange and only the index.html file of Wikipedia.com without the content!