On any modern system it's actually "sudo rm -rf / --no-preserve-root" and then entering your password while staring at the command.

"rm -rf ~/blue /" will not come close to deleting / unless you are in the habit of running every command as sudo, even ignoring the presence of --no-preserve-root

Much, much, much the worse is "rm -rf ~ /blue". I don't give a crap about 99% of the stuff outside of $HOME, but of course, the stuff in $HOME is the stuff that's trivial to destroy.

You're missing the point:

    $ cd dir where there are source files and temp files
    $ rm *.tmp # or so you think
    '.tmp not found'
    # too bad

Except when: (these are terrible lessons to learn)

1. You type it into the wrong system (D'oh)

2. You have run `mount --bind / /somewhere/else` then `rm -rf /somewhere` a week later

:(

It boggles my mind that --one-file-system is not the default :/

> Not really, a lot of novice unix users are of the habit of removing files with -rf switch. I cringe everytime I see it.

Every few days I remind myself of this.... then I have to delete another directory with a git repository in it, and end up add the -f in again

I run into this all the time, too. Now my -rf usage is almost always wrapped by this:

    rmgit()
    {
        git status
        read -p "Are you sure? " -n 1 -r
        echo
        if [[ $REPLY =~ ^[Yy]$ ]]
        then
            rm .git -rf
        fi
    }

I think this would be a bit better for interactive cases. Note: written just now, I haven't actually felt the need for this safeguard... yet.

    rmrf()
    {
        (echo "The following files are going to be deleted!!!"
         for FILE in "$@"; do
             echo "<<<" "$FILE" ">>>"
         done) | less
        read -p "Are you sure? " -n 1 -r
        echo
        if [[ $REPLY =~ ^[Yy]$ ]]
        then
            rm -rf "$@"
        fi
    }

Doesn't help against network filesystems mounted in subdirectories. --one-file-system (which really ought to be the default) prevents this.

What would be the "good" alternative ? I often tries "rmdir" or "rm -r" if the directory is not empty and very often there are some "protected files" so I add -f. Thus it happens that I directly lauch "rm -rf".

Watch it fail first, verify that the failure makes sense, check to see if there's a way to delete one file with -f before deleting the rest with -r. Use -rf only as a last resort, and only by appending the f to an already-failed command whose syntax you've validated.

More easily, "rm -rf ~" with a premature "Enter"

do the -rf after the directory to avoid this in future

Premature enter just results in:

[web@server /]$ rm ~

rm: cannot remove `/home/web': Is a directory

Hehe, I did something like that once, except that I typed "rm -rf ~ /blue/". There was no /blue/, but I managed to wipe out my home directory, and I did not have a backup. :-| It was on my personal machine, so at least I did not delete anybody else's files, but I still got burned hard enough to learn a valuable lesson.