Exit codes from the Java Virtual machine

Question

Hi,
I've been asked to write a C wrapper program on UNIX and Windows which launches java (or java.exe) with the appropriate command line options and jar files to run an application.
So far so good.
However, I can't find any documentation saying how the status code returned by java or java.exe is constituted. e.g. How do you tell an error returned by the virtual machine, such as NoClassDefFoundError due to a missing jar or entry point, from a status code returned by a running Java application?
Are the possible status codes returned by the JVM documented anywhere? Are they the same on UNIX and Windows? Should the Java application use a particular range of return status codes so they don't collide with the JVM's own?
Thanks in advance for any pointers on the subject.

Answer 1

Ah, I see, you're asking what if any existing codes are returned by the JVM implementation.Yep, that's it. I need to know that if the application chooses to use System.Exit to return (say) status code 2 meaning "your print job is queued", that the JVM won't ever return 2 meaning "couldn't find your application jar files" or some other generic condition outside the application's control.
I can move the application's return codes into a specific value range, as long as I can find one that is guaranteed safe for JVMs on both UNIX and Windows. Sounds like that's a bit optimistic. Thanks for the source code suggestion, but don't really have control over the customers' choice of JVM.