I am building a networked backup system that will allow remote offices to backup to a central server. I was planning on having each client zip up just the changed files and then send that zip file to the server, which would then merge the new zip in with the existing zip, creating a kind of incremental backup. I can' figure out a way to merge two zip files together without unzipping and re-zipping the files together, which could get to be a mess sense the zip files will contain directory information.
Does any one have a clue how to go about merging zip files? or is there a better solution I’m just not seeing?