Youtube-dl - Download YouTube Videos from command line in Ubuntu

Youtube-dl is a small command line program to download video from Youtube.
How to use Youtube-dl
Step 1. open terminal and type

$ sudo apt-get install youtube-dl
Step 2.Updating to latest stable version

$ sudo youtube-dl -U
Step 3. Download any youtube video

$ youtube-dl [youtube video URL]

Step 4. Give different file name to the video

$ youtube-dl -o video_name.flv  [youtube video URL]