You can use the following environment variables...
to set a proxy http the syntax to be executed in a session bash is as follows:
export http_proxy=http://[[user][:pass]@]proxyname[:port]
To set a proxy ftp:
export ftp_proxy=http://[[user][:pass]@]proxyname[:port]
if you want to configure these environment variables globally just enter the command without the definition export into the file /etc/profile oppure in /etc/environment.
