How To Set Proxy in Ubuntu terminal

If you are under a proxy server, and want to access net using http or ftp through Terminal,you will need to export http_proxy/ftp_proxy variables. 

 For a HTTP proxy, simply run the following command in a terminal

•  export http_proxy='http://proxy_username:password@proxy_ip:port " 

For a HTTPs and FTP 

•  export https_proxy=https://proxy_username:password@proxy_ip:port 
•  export ftp_proxy=ftp://proxy_username:password@proxy_ip:port   

If there is no username and password required for your proxy then simply remove the username and password section. 

• " export https_proxy=https://proxy_ip:port "

These settings are saved into  /etc/apt/apt.conf file .So you can directly add these variables using text editor .First open the apt.conf file

• " sudo gedit /etc/apt/apt.conf "

then enter the username,password,proxy_ip and port in given format

•  Acquire::http::proxy "http://proxy_username:password@proxy_ip:port ";
•  Acquire::https::proxy "https://proxy_username:password@proxy_ip:port" ;
•  Acquire::ftp::proxy "ftp://proxy_username:password@proxy_ip:port ";

Enjoy !!!!