Beej’s Guide to C Programming [pdf]

Post by jpcooper » Sat, Apr 24, 2021, 6:33 AM UTC

beej71 wrote: post #154

jpcooper wrote: post #129

Earlier quoted context omitted.

Is it beej or bj?

One syllable, typically. But either works.

Post by pjmlp » Sat, Apr 24, 2021, 6:37 AM UTC

beej71 wrote: post #127

gnuvince wrote: post #96

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What does "modern" C imply? AFAIK, there are not very many new language features; is it about organizing code differently than what one would learn from K&R?

I'm chuckling to myself at "there are not many new language features" because that's what I thought. There's fair amount added to the core since C89, actually... And if you include the library changes, game over! I had no idea how much had been added. More challenging is to find what's been subtracted. This no longer defaults to int: static i; And gets() is toast. Anyone know any others?

Post by Arch-TK » Sat, Apr 24, 2021, 8:58 AM UTC

mytailorisrich wrote: post #148

Arch-TK wrote: post #141

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Treating C as an abstraction over assembly is a surefire way to step into all the thousands of sharp edges C has. In fact I would hazard a guess that the majority of bugs found in software written in C are a result of programmers treating it as a portable assembler instead of a language for programming an abstract machine. So many incorrect assumptions arise as a result of telling people to treat C as a portable asse…

I was discussing pointers. I only commented in passing about C being portable over assembler. You could rephrase this as it being a language for programming an abstract machine and it would not change anything about my comment (nor would it change the fact that C is an abstraction over assembly) Thank you for your reply...

Post by klyrs » Sat, Apr 24, 2021, 4:41 PM UTC

skocznymroczny wrote: post #55

unwind wrote: post #28

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These are good points. I can sometimes feel that Python is more pointer-y (?) than people expect, with stuff like: a = {"one": 1, "two": 2 } b = a b["two"] = 99 print(a["two"]) The above prints 99, since "b = a" does not copy the value (the dictionary) but just the reference to the value ("the pointer", kind of). This is surprising to some people.

Reminds me of the Python trap that I fall into every few months because I forget about it: def foo(mylist=[]): mylist.append("a") return mylist mylist is only initialized once, so the function will actually return one more "a" with each function execution

  def foo(x, cache={}):
    if x in cache:
      return cache[x]
    val = cache[x] = x*x+1
    return val

Post by tom_mellior » Sat, Apr 24, 2021, 7:44 PM UTC

pjmlp wrote: post #163

thamer wrote: post #133

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Apart from the new features added in C11 or C17 that others have mentioned, both Beej's Guide and Modern C also cover threads and string encoding (neither of these topics are covered in K&R 2nd edition, as far as I remember). Beej's Guide also has a section on internationalization and one about date/time handling. But yes, the code is also quite different than in K&R which is relatively terse. See for example this co…

While experienced C programmers that care about security wouldn't even touch strcpy() . All those code samples will crash and burn if s and t point to the wrong locations, t happens to point to a string without a null terminator, or s points to a buffer not big enough to handle the string pointed by t.