What does an exitcode of null from a script imply?
Read the Javadocs on the getExitCode() of the ProcessExecutionResults class to see when exit code will be null:
http://git.fedorahosted.org/git/?p=rhq/rhq.git;a=blob;f=modules/core/native-...
/** * If the process finished, this is its exit code. Its numeric value has specific meaning that is custom to the * operating system and the program that was executed. * * <p>This will be <code>null</code> if the process was never waited on or if the wait time expired before the * process exited.</p> * * @return process exit code or <code>null</code> if it could not be determined * * @see SystemInfo#executeProcess(ProcessExecution) */ public Integer getExitCode() { return exitCode; }