3 ms·

> If you want conformity that's fine. What would you think if your company instituted a very specific dress code? Requiring specific trivial knowledge is just a

by strlen 16y ago

> If you want conformity that's fine. What would you think if your company instituted a very specific dress code? Requiring specific trivial knowledge is just as restrictive and constraining. It's not about hacker folklore, it's about a debugging technique. No one implies that this question is asked of every candidate. That's why these lists are useless. It's also not the way I'd ask a question about memory markers (I'd ask them about how they go about debugging such a problem and how the tools they use e.g., gdb and valgrind work), but it's a fair question to ask those claiming experience with or interest in low-level development much like it's fair to ask candidates who claim experience with data mining what the kernel trick is (...but it would be misleading to ask a Linux kernel hacker that question as that would mean something else to him, much as dead beef would mean something else to a data mining guru).

InclinedPlane 16y ago
Keep in mind, I'm responding specifically to the idea that "[explaining] the significance of ‘dead beef'" is a valid interview question. Have you done a survey of memory debugging experts to determine how common knowledge of "dead beef" is? It's not a knowledge question, it's a trivia question. A shibboleth. It is neither a necessary nor sufficient pre-condition for knowledge of memory debugging techniques and it probably has about as much correlation with them as asking whether they have read The Lord of the Rings.
- strlen 16y ago
  > It is neither a necessary nor sufficient pre-condition for knowledge of memory debugging techniques and it probably has about as much correlation with them as asking whether they have read The Lord of the Rings. It's a hexadecimal number, that should be quite obvious. It's a noteable and easy to notice one. Others may have used a different one (I used 0x12341234 for the task as others have used 0xdeadbeef) but it should be obviously what you'd use it for. Is it one of the better questions? No. Is it merely a shibboleth or a piece of trivia? When asked to low-level hackers, no.
  - InclinedPlane 16y ago
    When shorn of hexadecimal connotation as in the original question what value is there to it? If I ask someone verbally "what is the significance of dead beef" should I put any value in their either having already learned about 0xDEADBEEF or in their ability to appreciate that it could be a 32-bit word aligned hex value? If someone were to change the question to "what is the significance of bad food?" would it be considered equally valuable?
    - strlen 16y ago
      O is not a hexadecimal number - even if it was "BAD F00D" it still wouldn't be a full 32-bit word - it's also not use by existing libraries (libgmalloc) cafe babe, dada dada would just as well as dead beef In short, either you are familiar with magic numbers or you're not. If you're not, you're certainly not qualified to work on anything really low-level and may not be qualified to do C/C++ development in userland either (without strong evidence to the contrary).
- Locke1689 16y ago
  No it's not. If you don't know about magic numbers you don't know how the BIOS loads the kernel into memory. Period.

by strlen 16y ago

InclinedPlane 16y ago

Keep in mind, I'm responding specifically to the idea that "[explaining] the significance of ‘dead beef'" is a valid interview question. Have you done a survey of memory debugging experts to determine how common knowledge of "dead beef" is? It's not a knowledge question, it's a trivia question. A shibboleth. It is neither a necessary nor sufficient pre-condition for knowledge of memory debugging techniques and it probably has about as much correlation with them as asking whether they have read The Lord of the Rings.

strlen 16y ago
> It is neither a necessary nor sufficient pre-condition for knowledge of memory debugging techniques and it probably has about as much correlation with them as asking whether they have read The Lord of the Rings. It's a hexadecimal number, that should be quite obvious. It's a noteable and easy to notice one. Others may have used a different one (I used 0x12341234 for the task as others have used 0xdeadbeef) but it should be obviously what you'd use it for. Is it one of the better questions? No. Is it merely a shibboleth or a piece of trivia? When asked to low-level hackers, no.
- InclinedPlane 16y ago
  When shorn of hexadecimal connotation as in the original question what value is there to it? If I ask someone verbally "what is the significance of dead beef" should I put any value in their either having already learned about 0xDEADBEEF or in their ability to appreciate that it could be a 32-bit word aligned hex value? If someone were to change the question to "what is the significance of bad food?" would it be considered equally valuable?
  - strlen 16y ago
    O is not a hexadecimal number - even if it was "BAD F00D" it still wouldn't be a full 32-bit word - it's also not use by existing libraries (libgmalloc) cafe babe, dada dada would just as well as dead beef In short, either you are familiar with magic numbers or you're not. If you're not, you're certainly not qualified to work on anything really low-level and may not be qualified to do C/C++ development in userland either (without strong evidence to the contrary).
Locke1689 16y ago
No it's not. If you don't know about magic numbers you don't know how the BIOS loads the kernel into memory. Period.