C trivia - was Re: Dennis Ritchie has died

On Fri, 14 Oct 2011, Josh Dersch wrote: It DOES. As much as C "normally" does. (Bounds checking is not often considered important in C! It is EASY to crash almost any program that uses scanf(), or even gets() for keyboard input! ) It will continue until the value that has been copied is 0 It IS the code, that you've probably been using all along, of strcpy() . And THAT is the level of bounds checking that the "standard library function" has. BUT, I would prefer swapping 's' and 't' throughout the example, to make it easier for those not familiar with it to be able to think of them as "source" and "target". When I taught "Data Structures and Algorithms In C", meaningful variable names DID help students to follow what was going on. After we finished that (building a string copy from array notation spread out to THAT, and a trivial strcmp() ), we spent the rest of that lecture on "alphabetic order". Yeah, you know alphabetic order. Yeah. SURE. Q: But can you recite it backwards, WITHOUT SINGING, standing on one leg? A: Not while sober. Which order do YOU think the following belong in? (and why?) (and what order matches a sort based on strcmp() ? (and why?) ) : New York new compiler newsworthy two three (a hint) new world (deliberate white space, as a hint for New York/Newton) Int21h Newark C : An Introduction (proper bibliographic punctuation of subtitle) C: An Introduction Int3h New Hampshire Newton 800 Software (and WHERE in the phonebook was it (it was a real company)) 99 Ranch Market (and WHERE in the phonebook (it is a real chain)) (The college discontinued "advanced" programming classes while phone books still existed) Then they had an assignment (due in 2 weeks, but with discussion next week) to write their own strcmp() that could, under program control: ignore/pay attention to case ignore/pay attention to NUMERALS put numbers in numeric order, even if not at beginning/end of item place numerals in ASCII/numerical/phone book order ignore/pay attention to space ("order by letter"/"order by word" to OLDER librarians) ignore/pay attention to other "white space" and any other arbitrary characters Since strcmp()'s return value is "normally" only checked for 0 / <0 / >0 , I introduced them to the concept that it COULD, instead of a simple subtraction, return packed bitfield that would could be used by the calling routine to mimic strcmp(), but by masking bits (an earlier lecture) could identify if something was a match except for case, etc. The next lecture started in on sorting and searching algorithms. -- Grumpy Ol' Fred cisin at xenosoft.com