In another comment, OP said they checked the arch wiki, specifically https://wiki.archlinux.org/title/File_recovery. The arch wiki is a great resource; most of the information is not arch-specific and is useful for linux in general.

Regarding “let’s try sudo”: you should get familiar with sudo because it’s one of the most important linux commands. It runs a command with elevated privileges (it originally stood for “super-user do”). That means sudo isn’t actually the important part of the commands; it just means that the following commands (pacman and photorec) need elevated privileges. pacman deals with systemwide package management and photorec needs access to the raw storage device objects in order to recover files.

The attached image says “(see more with ‘–help’)”. And, in fact (I just tried it), the output of --help contains a lot more detail.

Edit: for more information, fd uses the command line argument parser library clap, which has both help and long_help properties for arguments, which are displayed for -h and --help, respectively.

If it’s on Github doesn’t that make it OS?

No, when talking about open source software, people typically refer to a definition along the lines of the Open Source Initiative’s Open Source Definition. To distinguish this from software that you can only see the source (but don’t have rights to copy and modify it), they’ll use the term Source Available Software.

I don’t really know about the software you guys were talking about, but the repositories I looked at used the MIT license, which is OSI approved. However, that might not be all of the code they use. It’s not uncommon for a company to open source a “base” version, but they deploy a version that’s altered from that (I’ve got no clue whether they do or don’t).