Force s3cmd to use wireless adapter instead of ethernet

I need a script to sync all data in a folder to S3 I think I have the script sorted but my only issue is tha开发者_运维技巧t I using the ethernet connection to get the files for the upload to S3 but only the wireless has access to the internet. Is there anything I can add to the script to force it to use the wireless connection?

USERNAME='/home/user/user.ip'
while read USERNAME; do
  s3cmd put -r $USERNAME s3://s3tools-demo/some/path/
done < $USER