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Talk:Longest string challenge: Difference between revisions
→bounds checking in C, take 2
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=== bounds checking in C, take 2 ===
:I do not think that C code with buffer overflows should ever be considered to be simpler than C code that guards against them. It might be faster, but any apparent simplicity is deceptive since the possibility of buffer overflows pushes complexity out onto the user. That said, gets() here requires strcat(), because gets() drops the end of line character. Meanwhile fgets() does not trim off that character. And bounds checking could be implemented using memset() and then using the implementation's cmp() between a reference and an appropriately choosen spot near the end of buffer. So if we are will to pay the minor increase in complexity to use gets instead of fgets, I am not sure why we are not willing to pay a few extra lines to get an implementation without buffer overflow. --[[User:Rdm|Rdm]] 16:14, 17 August 2011 (UTC)
:: 1) I added a second version without buffer issues. 2) With fgets, you still need to check if the line is too long and was truncated; if it is, we are pretty much screwed and need to be able to read in the rest of the line and append it to the line buffer, which is a lot of work because of the "no arithmetics" clause. The second method does handle arbitrarily long input, but see how much more complicated it is.
:: It's not that I particularly love gets or buffer overruns, and "faster" is totally not a concern for this task, the key issue is how easy it is to read the code. The original C code was really just demonstrating how to compare the lengths of two strings without directly measuring them, and I deliberately did not pretend it was safe code (I've ''never'' used gets before); declaring const and fgets, to me, feel like false promise of safety.
:: That said, if you can check bounds and truncation correctly without making it overly complicated, feel free: I can't think of a way to do it without integer math, like in the second solution. --[[User:Ledrug|Ledrug]] 18:27, 17 August 2011 (UTC)
== Boring solution v. restrictions ==
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