Copy only new and changed files to another Mac?

[I Need a Drink]

I have an iMac and a Mac Mini and I'm also getting ready to buy a MacBook Pro. My primary machine, the iMac, is where I do a lot of my work and where I keep a lot of my files. However, I want to be able to access these files from the other devices. I don't want to store them in the cloud as there is sensitive business info that I do not want there. I also don't want to turn on file sharing. I can transfer the folders when I need through a Flash Drive.

What I want to know is when I copy the files and folders to the Mini or the MB is there a way to tell the system only to copy new files or ones that are more recent rather than overwriting every file? I don't want to constantly have to copy GBs worth of data to keep my systems current and this would also keep wear and tear down on my SSDs.

 

[Weaselboy]

There is a command line tool called rsync that comes with your Mac that can be configured to do exactly what you want. But you will have to figure out the correct command. There are GUI overlays (apps) like this that will make it easier.

 

[dianeoforegon]

See these links to store your files on an external drive.

https://thomashunter.name/blog/move-special-os-x-user-folders-to-external-drive/

http://mattgemmell.com/using-os-x-with-an-ssd-plus-hdd-setup/