[Bug-tar] Exit status for recoverable errors

[Adrian]

Hi. This is a suggestion/improvement for the exit status of "tar".

We have a backup script that launches tar and checks the exit status. If
the exit status is non-cero (error), the script logs the stdout and
stderr to a file, and then it sends a email to a person.

Our problem is that the exit status value doesn't difference between
recoverable (warnings) and non-recoverable (critical) errors.

We obtain frecuently a "file changed as we read it" error, that is
recoverable (a warning) since "tar" continues and the backup is made
perfectly. But the exit status is non-cero (2), and the script logs and
warns us every time the recoverable error appears.

So our suggestion/improvement is to distinguish recoverable and
non-recoverable errors in the exit status. For example, use "3" value
for recoverable and "2" for non-recoverable errors. In this way, scripts
will be able to detect critical/non-recoverabe errors and do different
things.

Thanks for your time