JDB and the attach option

Question

I was asked this question on a test and I'm not sure what the answer is and I'm having trouble finding it here and anywhere else online. So I hope someone on here can give me a quick answer and a quick explanation:

You debug a Java program using the following command:

jdb -attach 2121

Based on the scenario above, the command that is unavailable during your debugging session is:

a) print. b) threads. c) run. D) dump. e) cont.

I know attach is used with jdb to connect the debugger to a specific process and VM. But I don't know which process would be unavailable. I'm pretty sure you can use multiple threads within a VM, so that discounts b and c. and I don't know why you couldn't use print or cont -- that's a and e. and last would be dump, but I'm still not sure.

Anyone know. Thanks.

Answer 1

The answer is: c) run. Since "This command is available only when jdb launches the debugged application (as opposed to attaching to an existing VM)". See jdb manual page for details.