i never found !! useful at all when i can just use up arrow to get the entry i want. it becomes more interesting when you can recall older commands, but then too i prefer search because i want to verify what command i am going to run.

and i only use sudo to open a root shell. never to run anything directly. i don't want normal and root commands mixed in the same history.

i could keep sudo commands out of the history, but then i don't have any history for stuff done as root.

with tmux i can switch terminals easily, so i am also not tempted to run things as root that i shouldn't despite having a root shell open.

I have a bash key binding, Ctrl+Y, that prepends sudo to the current command and submits it. I also don't use sudo-rs. No one has died yet.

Decades ago, i used a small dns host. I wanted to switch a personal site and they just couldn't get the final step of the transfer to work. A ton of "try now" emails spanning several weeks.

Then one day, I was trying to setup MySQL on a personal Linux machine, and it wouldn't let me use my "standard password" for the admin account. I knew I could just use a different one, but I really wanted to know what the problem was. Took a long time, and I don't remember how I figured it out, but I eventually tracked it to the password ending with '!!'.

It took a while to put it together, and I never confirmed with the dns host support it's what fixed the issue but, I changed my password there, tried the transfer again, and it worked without any help from support. I suspect my plaintext password played some part in a script used in the transfer process, and was outputting the previous command in place of the !! I wish I had asked them if that was it, but if it was, they would have to admit to having my plain text password, or lie about it.

Prepend your command with a space and now your command is not saved in the history.