How is it possible to pipe out
wget's downloaded file? If not what alternatives should I use?
Or use curl, where it's the default behaviour.
There are other methods you can use instead of wget and curl:
You can use lynx:
# lynx -source http://www.google.com
# w3m -dump_source http://www.google.com
and libwww-perl comes with a handy program called GET (as well has HEAD and POST, which do what you think they do)
# GET http://www.google.com
I suggest to use Aria2. It's powerful downloader.