Set a proxy for terminal on Ubuntu

First:
$ ssh -D 8080 user@remote_server_ip

For example:$ ssh -D 8080 [email protected]

(you can also use Shadowsocks-qt5)

Second:

$ sudo apt install privoxy

vi /etc/privoxy/config
Add these two lines:

forward-socks5 / 127.0.0.1:8080 .

forward-socks4 / 127.0.0.1:8080 .

You can use the following command to check which port is using :
$ sudo netstat -ntlp | grep LISTEN
You can find port 8080 is on and used by privoxy.

Third:

Open a terminal:

$ export ALL_PROXY=http://127.0.0.1:8118

Test:

use this to find if your proxy is working:

$ curl -v google.com

Besides: I find a tool to check whether the server ip is blocked, sometimes may useful:
ping.pe