I aim to hide data into .txt and .xml files, from Linux OS, aand keep it readable on any OS.
With Apple OS (OS X), I used to write 'secrete' data into files (actually in the Resource Fork of the file), but out of the content of the file. Example: a file bob.txt, when you open it with Text.app it displays "hello you", but I placed undisplayed text into bob.txt (e.g.: "my_hat_is_redwine").
How to "HIDE" textdata with Unix/LinuxTerminal, outside of the content ?
Conditions are: - opening the file, - zero content alteration.
I have been looking for EOF (end of file), but it does NOT exist on Linux (EOD is an old stuff, very old).
I think about
setfattr, that's quite ok but I feel sure there is a deeper/stronger way.
I mean, editing the full file bits chain, and adding bits between content and metada, for instance.