Note: The first 3 episodes of the interview series can be found here, here and here.
Question 1:
You have the shared document open and the phone rings. The interviewer, at the other end of the line, starts with a thick accent:
– What does ls * do?
You cannot believe your ears: it sounds easy. Really easy. So you answer in the line of “it lists all the files in the current directory”. The interviewer follows up with one or 2 questions on how it really works and you answer about the star being passed as a parameter to ls and how the binary interprets it in some way that it gets the entire directory walked over and its contents listed. Simple!
Note: this text is about Systems Programming on Linux platforms.
This type of interview is focused on finding out what do you know about what happens below the “command line” surface. Down there things can get messier, as processes get created, terminated, the output gets collected, system calls are performed. Things get complicated really fast for the unaware or the unprepared.
Let’s take for example a single command that is being run:
$ ls
This is a classical interview question, asked for more than 15 years now. I’m not sure if anyone still asks it in 2016, but it’s still interesting to see the answer. So, what happens when this is being run? (No, not the file list display).
From the beginning:
So – you got yourself an interview with Googamazbook and you are set on failing it. Or maybe you’re not set but you’re simply not trusting the 99.9+% failure rate that is typical for these companies and you want to be in some sort of control over you failing the interview. Either way, you got to the right place!
1st stage failing
Well, the 1st stage is the screening by the recruiter. This is actually pretty hard to fail if you are conditioned from school, like many of us, to always give the (expected) correct answers. Some people are failing at this stage due to not “speaking the same language” as the current employees of the company, but they are a minority.
So if:
you’re set on failing the recruiter screening;
you got yourself a lot of experience;
you were pretty good with quizzes during the school years:
… it’s basically impossible to fail on this one. Sure, you can make up wrong answers, but that’s just lame. Let’s simply forget about it and go to the next stage.