Note that it's not all stuff that you can just look up: although you can look it up, it might not be obvious that it needs to be looked up. I had no idea there was a difference between `int f()` and `int f (void)`, and if that ever caused problems for me I doubt I would have been able to track it down easily.
"A gentleman is someone who knows how to play the bagpipes, and doesn't."
Understanding the memory model and execution model is a big plus, because it lets you write correct and efficient code (and if you are using C you care about correctness and efficiency). Recalling arcana about the C99 standard is just overkill and asking someone to pull stuff like that out of a hat in an interview is asking too much IMO.
Suggestion: enable -Wall and treat warnings as errors.
gcc -v shows that it's been configured with --disable-werror
sizeof-test.c: In function ‘main’: sizeof-test.c:5:3: warning: format ‘%d’ expects type ‘int’, but argument 2 has type ‘long unsigned int’
Compilers have warnings so that you don't have to remember archaic bits of C. :)
The parenthesis you usually see after it are part of the argument, which for type names looks like a cast to the type in question. Like any other cast, the syntax is the type name in parenthesis.
Apologies if you already knew this.
It's only a net win if the price is right and the project requires such knowledge (in the case of C, mostly likely the trade-off would be a bad one, experience at that level comes at a steep price, fixing bugs due to a lack of knowledge about what happens 'under the hood' is expensive too...).