SET UP PROXY - SHELL
to set up the proxy from the shell you have to exectue
$export http_proxy="<proxyadress>"
example:
$export http_proxy="http:192.168.122.4:3128"
Rember that this variable is temporary and it is bound only to the user who executed the line. If you want to use as sudo user you have to execute the same command as sudoer (sudo export...).