C Strings and my slow descent to madness

Re:C Strings and my slow descent to madness by coldpie on Thursday April 06, 2023 @09:26AM (#35468022)

It's unfortunate the author put the arrays-are-pointers thing so early in the doc, as that's a very beginner-to-C mixup and really nothing at all to do with strings. Otherwise, yep. It's pretty bad. C is a great language, but its string handling is definitely garbage. You get used to it pretty quick, and it's not hard to write a handful of sane wrappers or a simple string library for your own use, but the standard library's terrible string functions are an unending source of bugs.

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Re:C Strings and my slow descent to madness by gpderetta on Thursday April 06, 2023 @10:21AM (#35468650)

I don't see any mention or insinuations of arrays-are-pointers anywhere in the article. Am I missing something?

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Re:C Strings and my slow descent to madness by coldpie on Thursday April 06, 2023 @10:38AM (#35468888)

This bit:

    But you might be asking. “Why can’t I just assign the source variable directly to the destination variable?”

    int main() {
      char source[] = "Hello, world!";
      char* destination = source;
    
      strcpy(destination, source); // Copy the source string to the destination string
    
      printf("Source: %s\n", source);
      printf("Destination: %s\n", destination);
    
      return 0;
    }
    You can. It’s just that destination now becomes a char* and exists as a pointer to the source character array. If that isn’t what you want them this will almost certainly cause issues.

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Re:C Strings and my slow descent to madness by unwind on Thursday April 06, 2023 @12:52PM (#35471093)

This is almost a cliche among many C language lawyers and/or Stack Overflow answer-rich people and I know you mean well, but: arrays are not pointers.

In some contexts, the name of an array decays to a pointer to its first element. That is a better way of putting it, and it's a (much) weaker statement.

Edit: if they were the same, this code:

    int foo[] = {1, 2, 3};
    int *bar = foo;
    printf("%zu and %zu\n", sizeof foo, sizeof bar);

Would print the same valde twice, but it doesn't. On Ideone [1] I got 12 and 8.

[1]: https://ideone.com/CP7WTu

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Re:C Strings and my slow descent to madness by int_19h on Thursday April 06, 2023 @03:52PM (#35473497)

This also makes a big difference once we start talking about pointers to arrays.

    int a[] = {1, 2, 3}
    int (*p)[3] = &a; // ok
    int *q = a; // not ok

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Re:C Strings and my slow descent to madness by strkitten on Thursday April 06, 2023 @05:03PM (#35474405)

Nothing wrong with your third line. Did you mean something else?

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Re:C Strings and my slow descent to madness by int_19h on Thursday April 06, 2023 @05:20PM (#35474635)

I forgot the &; comment updated now, and I added another example.

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Re:C Strings and my slow descent to madness by strkitten on Thursday April 06, 2023 @05:27PM (#35474732)

Got it, thanks!

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