Assume you are heavily rely on Terminal interaction, whatever Bash or Zsh, if you wanna a quick switch from the console, you may try this.
Here is an example of using Zsh shell from your Linux distribution:
As the script mentioned, add it into ~/.zprofile, and type:
Then you can easily set the HTTP_PROXY/HTTPS_PROXY with one command:
Then follow the screen to set up your HTTP Proxy accordingly.
Somehow you need to switch off the proxy, simply use
Last but not least, use kill_http_proxy to remove the stored HTTP Proxy config in your home folder.