2022/04/08
What hardlinks are: direct references to inodes. A hardlink can’t reference filesystem objects that don’t have inodes, such as directories or ports, and aren’t portable across different hardware devices even with the same filesystem layout (I think).
Also, the opposite of mount(8) is not unmount, it’s umount >:(
gzip -vt $path_to_file checks the validity of a gzip archive: see
https://unix.stackexchange.com/questions/359303/check-validity-of-gz-file