I wanted to transfer a lot of files and resume any failed file transfers and not overwrite duplicate files
After searching the ‘Net and finding a LOT of recommended methods, I found a simple method the did not overwrite existing files, and resumed any partial files, but updated all changed files
SFTP using startup options to determine how to handle file transfer
sftp -a -r user@site.com
tells sftp to resume file transfers and copy recursively
Problem solved, now I can upload a directory to my site and have only new files transfer’ed, and also have sub directories copied
This allows me to develop files on my development servers, and easily upload all new files to my production server