On Wed, Dec 11, 2019 at 07:12:57PM -0500, D. Hugh Redelmeier via talk wrote:
"/*" matched every name in / (not dotfiles)
The last name matched was /var. We know this because of the list that Lennart gave us later -- we might have had to figure this out ourselves.
Ignoring the clashing names and /var, everything that was in / was moved to /var.
Clearly some fundamental tools are impaired.
The first reason (but not the only one) is that /bin has been moved to /var/bin (but we may not realize this right away).
Note: usually echo is built into the shell so echo * would work as a substitute for ls
Yes echo * is very important.
| So what do you do now?
Take a break to calm down. Anything you do in a panic is likely to make things worse.
Rebooting would have made it a lot harder for sure. Fortunately the guy came and asked me for help instead.
Make a plan. Before you take any step that might be irreversible. Exploring is OK.
It's true that this is an interesting problem. But getting tricky when confronted with an emergency isn't always wise.
Well it was only his test system, but it would have been annoying to have to recreate it.
I would probably boot from a live system on a USB stick, mount / somewhere, and look around. Fixing things from such a system is actually simpler than trying to do so from the busted system. You don't need a deep understanding of the mechanisms for run-time linking. You won't need to get the dynamic linker and libraries back onstream.
I am not actually sure that particular system can even boot from USB, and it has serial console only, no VGA.
A clean shutdown will be a challenge but it probably doesn't matter. After booting the live system, do an fsck on the original system's / to make up for a bad shutdown.
That's really nice to know. In many scenarios you would not know this.
That's for sure.
- this lets you figure out where everything went without any detective work (/var)
- this lets you figure out what must be moved back.
-- Len Sorensen