How to download videos from any site using terminal based command?

I want to download any videos form any site using terminal command , I know "youtube-dl" but it doesn't download videos from some sites like khan academy so, what is the best for that ?

You can also use youtube-dl for that. Just copy the url of the video. In case you don't know about the link. Just right click & see View Frame Info you'll see the video url there. Then

youtube-dl videourl

You can use wget for that.

type the following command on terminal:

 apt­-get install wget

Download a single file using wget.

 wget "your video url link"

You can use movgrab.

To install Movgrab:

sudo add-apt-repository ppa:nilarimogard/webupd8
sudo apt-get update
sudo apt-get install movgrab

Check this for more information

Or you can download the source, extract it and compile it:

 wget https://sites.google.com/site/columscode/files/movgrab-1.2.1.tar.gz
 tar xvf movgrab-1.2.1.tar.gz
 cd movgrab-1.2.1/
 ./configure
 make
 sudo make install

You could use this:

wget --force-yes "'echo$http:url'" 

and it might work fine this way.