Namely, de-facto, or one of, in Linux. Mature. No GUI. Open-source and free.
What is it? GPG or anything else?
For a separate file(s), or directory(ies), and not for the entire disk or partition.
If you want per-directory encryption, there are several options. This front-end project lists a bunch of them in its Supported Backends section.
(Full disk encryption does have a single conventional answer: LUKS. Many distros offer to set this up at install time.)
You’re posting in a programming community, though, not a linux help community. Are you looking for a library for use in software you’re writing?
“I don’t want to encypt them in-place because I’ll be uploading them onto a server, copying them on an external drive.”
Describe your use case.
- backups, non-incremental ones
- prevent others from viewing information that may be sensitive
- encrypted files and directories will then be copied over to external drives and third-party servers
re-read my question carefully
Sorry I’m not sure I understand what it is you think I’m missing. It’s FOSS, works on Linux, has a CLI, works for both files and directories… please enlighten me what I got wrong?
It’s got CLI too - alright. But is it any de-facto, mature, well-known, widely used? What gurantees that it’s as secure as openssl or gpg? It might have plenty of bugs and vulnerabilies.
Perhaps https://rclone.org/crypt/