I install eggplant on my mac, can I use eggplant for automation on this mac itself?
Yes.
Set up a second user account and enable fast user switching. Install OSXVNC and set it to launch on login (don’t start it in service mode). Once you log in to that account, switch back to your main account, and your machine should show up in the eggplant connection list. Be warned, it is very process and memory intensive, and you may experience timing problems that you do not get when running on a separate machine.
You can also use Eggplant/ST to automate on the same user account, although it is a bit tricky. First off, do as the brilliant Allen (the gent that answered your question) mentioned, and use Eggplant to develop a script that will run against a Virtual User SUT. Then when it is done, run a VNC Server under your local account (not the virtual account). Finally, make a connection in your Eggplant script to the localhost and run either from EP or the CLI your script. Watch things fly.
As an example recently on a nationwide Verizon and Sprint comparison EVDO offering test, I wrote a script to repeatedly hit the www.speakeasy.net/speedtest/ site and screen scraping (see previous posts of mine in the Useful SenseTalk Functions) to gather metrics. Stored into files, and used later to prove remote access support concepts to management. Don’t know if they loved it, but it was indisputable info, and all done on one account, with SenseTalk and Eggplant.
I have done as brilliant Allen successfully!