This will automatically set the proxy variables when you launch a bash shell. At any time you can type
proxy_off to disable them.
You may need to hardcode your password, proxy server, and proxy port on line 11. Just replace each
$VAR_NAME with the actual value.
Put this file in your home directory. Make sure the file is called
.bashrc with nothing before the dot — if you're on Windows, try saving it from a decent text editor like Sublime Text or Notepad++ as Explorer will not let you name a file in this way.