That is very useful. You are right; I was assuming a non-attached TTY; however, it could very well be a closed/re-directed stdout. The NetBackup client does fun things with stdout/stderr for logging and data transfer. I will run some tests tomorrow to check. The scenario is quite simple. The NetBackup client runs a pre-script on backup. I use this pre-script with dump-able databases (oVirt, MythTV, Unifi, etc..) like this to create the backup file, then the backup program scoops up the generated file(s), and finally the post script cleans up. The pre-script is just calling: /usr/bin/engine-backup --mode=backup --file=$outf --log=$outl --scope=all You are right about output being run earlier, so yes it should have caused problems earlier? I only tested at the very end. From the code: do${MODE} ec="$?" log "EC: ${ec}" output "Done." ec="$?" log "EC: ${ec}" The exit code was 0 in the first one, but flipped to 1 after the output line. What I didn't test was what it looks like right after the earlier output lines. It could be the case that it gets set to 1, but then gets reset to 0 by the actual backup, before anything tests for it again (or it's time to exit). And I had tried a "2>&1 >/dev/null" wrap before, and tried to run it from cron -- none of which I could get to work either. I will play around some more. -Edmond