Where does script output go to (difference between BEFORE and AFTER?)

drwtsn32 · April 16, 2020, 3:25am

Welcome to the forum, @S1dney

stderr is captured in either --run-script-before or --run-script-after but all that it does is include the output in Duplicati’s own logging mechanism.

stdout on the other hand is only captured in --run-script-before. It’s designed to let a backup script adjust parameters before the backup runs. Duplicati will parse stdout looking for strings that start with -- so it can adjust parameters.

You can see an example here:

github.com

duplicati/duplicati/blob/master/Duplicati/Library/Modules/Builtin/run-script-example.sh#L145


	# If the operation is a backup starting, 
	# then we check if the --dblock-size option is unset
	# or 50mb, and change it to 25mb, otherwise we 
	# leave it alone
	
	if [ "$OPERATIONNAME" == "Backup" ]
	then
		if [ "$DUPLICATI__dblock_size" == "" ] || ["$DUPLICATI__dblock_size" == "50mb"]
		then
			# Write the option to stdout to change it
			echo "--dblock-size=25mb"
		else
			# We write this to stderr, and it will show up as a warning in the logfile
			echo "Not setting volumesize, it was already set to $DUPLICATI__dblock_size" >&2
		fi
	else
		# This will be ignored
		echo "Got operation \"OPERATIONNAME\", ignoring"	
	fi


elif [ "$EVENTNAME" == "AFTER" ]

stdout is never written to Duplicati’s logging mechanism that I can see.