Is there anything that can help me launch an app or command-line tool without internet or network access even when I'm connected to the internet? (so that I can use other apps with Internet, and block access for some apps) Like a firewall? Or something that intercepts the syscalls, something like maybe?
cp
) can start without Internet access. However, the github link seems to simulate the--dry-run
option onrsync
, but your question asks for "starting things while not connected to the Internet". You may wish to edit your question to make it a bit clearer.