Document return codes for non-interactive qsub

[pinkwah]

We are implementing a "driver" that uses OpenPBS to schedule jobs in the way our program expects and with the ability "do the right thing", like resubmitting on known issues.

We want to distinguish between user error (eg. queue does not exist) and known network errors (eg. connection refused). In the case of network errors, we wait and resubmit at a later time. We have noticed that the following error messages seem to have consistent return codes:

• "Invalid Credential" (171)
• "Premature end of message" (183)
• "Connection refused" (162)

We'd like to run OpenPBS's qsub and check the return code rather than searching for error strings in the stderr output, but these errors are not documented in man qsub. Is it possible to document the return codes so that we can future-proof this?