Delete duplicated contents from files

I have many backups of a same file. Is there a way to transform that into incremental backup? Those files aren't exactly the same (not same timestamps sometimes, sometimes new data appended here and there) I can't just search for dupes files, and I can't just delete old files for the new one, because sometimes the old one have data not here anymore I want a way to delete duplicated content from files. So there will be unique data across all the files. Ideally that would be merging, because if I just delete bunch of datas, the file would be unopenable, because sometimes theres duplicated formatting datas The problem is idk if new datas are purely by lines, or sometimes in the same line. It's not just a story about dupe lines, sometimes it's a part of the line who is duplicated Do you have any ideas?