Structures, and pointers to structures

This is a discussion on Structures, and pointers to structures within the C Programming forums, part of the General Programming Boards category; Ok, heres my problem. I made an array of pointers to structures, i initalized the array of pointers to structures ...

  1. #1
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    Structures, and pointers to structures

    Ok, heres my problem.
    I made an array of pointers to structures, i initalized the array of pointers to structures by using the address operators to obtain the addresses of the array.
    so i did something like this:
    Code:
    struct bla blaStruct1 = {
    //ect
    };
    struct bla blaStruct2 = {
    //ect
    };
    struct bla blaStruct3 = {
    //ect
    };
    struct bla *ptrs[] = {&blaStruct1, &blaStruct2, &blaStruct3};
    
    char *x = &ptrs[0]->atwodemensionalstringarray[0][0];
    when i run the code i get a SIGBUS error, which if i remeber correctly is telling you that you are accessing memory that you are not supposed to. So what i am i doing wrong? I want to point to the char at [0][0] in structure that is in an array of pointers to structs. If anybody could shed some light on what i am doing wrong that would be great!

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    char *x = &ptrs[0]->atwodemensionalstringarray[0][0];
    you problem lies in this statement..lets have a look. ptr[0] itself is a pointer to a variable of type struct bla. now, in you statement, you say &ptr[0] which means address of the pointer itself, and not the address stored in ptr[0], which is the address of blastruct1. thus, you are trying to access something at the address of the pointer, which you are not supposed to use..the correct way would be..
    Code:
     char *x = ptrs[0]->atwodemensionalstringarray[0][0];
    note that the & sign isnt there in the statement..
    Last edited by PING; 03-30-2005 at 12:32 PM.
    Code:
    >+++++++++[<++++++++>-]<.>+++++++[<++++>-]<+.+++++++..+++.[-]>++++++++[<++++>-] <.>+++++++++++[<++++++++>-]<-.--------.+++.------.--------.[-]>++++++++[<++++>- ]<+.[-]++++++++++.

  3. #3
    Registered User hk_mp5kpdw's Avatar
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    What's more is that if atwodemensionalstringarray[0][0] is a character and you are trying to assign that to a pointer it will not work. I'm guessing you can probably get rid of the last [0].

    Code:
    char *x = ptrs[0]->atwodemensionalstringarray[0];
    However, without actually seeing the definition of your bla struct it's just a guess.
    "Owners of dogs will have noticed that, if you provide them with food and water and shelter and affection, they will think you are god. Whereas owners of cats are compelled to realize that, if you provide them with food and water and shelter and affection, they draw the conclusion that they are gods."
    -Christopher Hitchens

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    However, without actually seeing the definition of your bla struct it's just a guess.
    True, but i guess, that we can leave it to the OP to think it out
    Code:
    >+++++++++[<++++++++>-]<.>+++++++[<++++>-]<+.+++++++..+++.[-]>++++++++[<++++>-] <.>+++++++++++[<++++++++>-]<-.--------.+++.------.--------.[-]>++++++++[<++++>- ]<+.[-]++++++++++.

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    Thanks!

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