How to pass system network through a proxy?

After geph-cli gets connected, we can set http_proxy in a bash session and subsequent commands are passed through geph's proxy (by default localhost:9910).

How to force all system network to use this proxy? (the option of system-level doesn't work)

I think we have to pass a PAC file to the network manager.

1- How can one generate this PAC file?
2- There is a pac binary with only on/off switches in the archive but relevant sources for it is not available on the Github page. Is it possible to export the pac script with that binary?

@nullchinchilla @Chocolate Sorry for ping. Any ideas on this?