[fabianhjr]

`rm -rf /` does have a safeguard:

> For example, if a user with appropriate privileges mistakenly runs ‘rm -rf / tmp/junk’, that may remove all files on the entire system. Since there are so few legitimate uses for such a command, GNU rm normally declines to operate on any directory that resolves to /. If you really want to try to remove all the files on your system, you can use the --no-preserve-root option, but the default behavior, specified by the --preserve-root option, is safer for most purposes.

https://www.gnu.org/software/coreutils/manual/html_node/Trea...

[layer8]

That was added in 2006, so didn’t exist for a good half of its life (even longer if you count pre-GNU). I remember rm -rf / being considered just one instance of having to double-check what you do when using the -rf option. It’s one reason it became common to alias rm to rm -i.