How do I configure proxy settings for a local system?

How do I configure proxy settings for a local system?

I would like to set the proxy settings for the http server running on my local machine on my laptop using the command line, so as to configure the proxy settings for apache, nginx or whatever.

Where is the file that holds the proxy configuration so I can change it? Thanks. The settings are stored in ~/.netrc and you probably have a netrc file under you home directory with the content machine hostname.example.com loginname
Where you replace hostname,loginname with your values. You also want to read about proxy in UNIX world as well and get in know all the terminology (like socks proxy as well).