Getting a unique identifier

[davbeck]

How do I get a unique identifier for a computer with cocoa? Or how can I tell that my application is running on a different machine?

[Wes]

MAC address seems like a good choice here.

From the terminal you can do ifconfig en0. You can make a system call and parse that. I don't know the Cocoa API but I assume Apple will have a wrapped that too, potentially here:
http://developer.apple.com/documentation/Networking/Conceptual/SystemConfigFrameworks/SC_UnderstandSchema/SC_UnderstandSchema.html#//apple_ref/doc/uid/TP40001065-CH203-CHDDEDFJ

[MrFusion]

MAC address seems like a good choice here.

From the terminal you can do ifconfig en0. You can make a system call and parse that. I don't know the Cocoa API but I assume Apple will have a wrapped that too, potentially here:
http://developer.apple.com/documentation/Networking/Conceptual/SystemConfigFrameworks/SC_UnderstandSchema/SC_UnderstandSchema.html#//apple_ref/doc/uid/TP40001065-CH203-CHDDEDFJ

A MAC address can be changed. Don't use it for security applications.

[Wes]

http://developer.apple.com/samplecode/GetPrimaryMACAddress/listing1.html

There's a little code.

I guess you could also get the serial number:
http://discussions.apple.com/thread.jspa?threadID=1906402&tstart=105