To use a proxy on the Linux command line, the environment variables http_proxy, https_proxy, or ftp_proxy have to be set, depending on the traffic type.

To do this effectively, the following commands have to be run:

$ export http_proxy=http://127.0.0.1:8080
$ export https_proxy="https:// 127.0.0.1:8080"
$ export ftp_proxy="http:// 127.0.0.1:8080"

You can check the current proxy settings via the env command:

env | grep -i proxy