macOS how to reject Virtual disk when device unplugging from usb port

[MayPeng]

I have a usb device , when it plug into the mac , it will appear a virtual disk .I want to reject it when unpluging device from the mac. How to reject Virtual disk when device unplugging from usb port by programming.

Thank you!

 

[lloyddean]

This'll be interesting!

 

[robbieduncan]

What is a virtual disk? What do you mean by "reject"? If you mean eject (a totally different word with different meaning) then what you want is impossible: you cannot eject the device once it's been removed: you must eject before removal.

 

[balamw]

http://developer.apple.com/library/...nceptual/OperatingSystem/OperatingSystem.html

and

man diskutil

B