Detecting upload success/failure in a scripted command-line SFTP session?

If you batch your SFTP session, the exit status $? will tell you if it's a failed transfer or not.

echo "put testfile1.txt" > batchfile.txt
sftp -b batchfile.txt user@host
if [[ $? != 0 ]]; then
  echo "Transfer failed!"
  exit 1
else
  echo "Transfer complete."
fi

Edited to add: This is something we use in a production script at work, so I'm sure it's valid. We can't use scp because some of our customers are on SCO Unix.