Any additional questions anyone can think of?
Having that said, most of the questions from "general questions" part come either from assuming that the candidate is dumb and possibly doesn't understand how computers work or from some lousy layman psychology.
Many of the questions further down are incorrectly assigned. "What is an A record?" is not a Linux-related question, and git is hardly a "devops tool".
Very poor list, in my opinion. In an interview you need to assess whether the candidate can do the job. Since the only heuristics available to the interviewer is how the candidate did in the past, the interviewer needs to allow candidate to show what he has done, how, and why.
And just for fun:
> A careless sysadmin executes the following command: chmod 444 /bin/chmod - what do you do to fix this?
My favourite way of fixing it is by running /bin/chmod. It blows minds of most smart-asses who ask this question.
Uhm, no? I've only seen it in recent CentOS (older versions didn't have it), and maybe Fedora does this as well.
> I think the question is asking you to use /lib/ld.so, but it's a bit of a weird question to ask.
Not really. You can do it in any number of ways, including using Perl/Python/Ruby, writing a short C program, or overwriting another file with execution permissions. My favourite way is a surprise to most people only because they don't know how ELF binaries work.
Arch, Ubuntu, Debian all do it.
> Not really. You can do it in any number of ways, including using Perl/Python/Ruby, writing a short C program, or overwriting another file with execution permissions.
Only the last one is a clever solution. "Just write a program" isn't a fun answer. :P
> My favourite way is a surprise to most people only because they don't know how ELF binaries work.
What do you mean? They didn't know there's a copy of the same binary?
>> Uhm, no? I've only seen it in recent CentOS (older versions didn't have it), and maybe Fedora does this as well.
> Arch, Ubuntu, Debian all do it.
I haven't checked Arch, but neither Ubuntu 16.04 nor Debian Jessie haven't created /bin as a symlink.
>> You can do it [restoring execution bit on /bin/chmod] in any number of ways [...]
> Only the last one is a clever solution
On interview you don't need to have the most clever answer. It's better to show you understand the mechanisms underneath by having several sensible ways.
> What do you mean? They didn't know there's a copy of the same binary?
No, I meant this: https://news.ycombinator.com/item?id=11627670
And there is no copy of the same binary.
Odd, I could've sworn they did. I stand corrected.
> > What do you mean? They didn't know there's a copy of the same binary?
> No, I meant this: https://news.ycombinator.com/item?id=11627670
> And there is no copy of the same binary.
That's what I said, you use the ELF interpreter. :P
> My favourite way of fixing it is by running /bin/chmod. It blows minds of most smart-asses who ask this question.
----
Not sure what I'm missing here?
$ docker run -it ubuntu
# chmod 444 /bin/chmod
# /bin/chmod
bash: /bin/chmod: Permission denied objdump -s -j .interp /bin/chmod
/lib64/ld-linux-x86-64.so.2 /bin/chmod