Assigning something

This is a discussion on Assigning something within the C Programming forums, part of the General Programming Boards category; Im trying to initialize code with keyCode and id with keyId respectively. Why do I get ['strcpy' makes integer from ...

  1. #1
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    Assigning something

    Im trying to initialize code with keyCode and id with keyId respectively. Why do I get ['strcpy' makes integer from pointer without cast]?


    Code:
    Key * ky_new(const char * keyCode, int keyId)
    {
     Key * ky = (Key *)malloc(sizeof(Key));
     if (ky != NULL)
        {
         strcpy(ky->code , keyCode); 
         ky->id = keyId;
        }
     return ky;
    }

  2. #2
    and the Hat of Guessing tabstop's Avatar
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    Because you don't have #include <string.h> at the top of the file.

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    Nope, I've double checked. I do have #include <string.h> .What's the problem then?Thkc

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    Not clear can u explain it further and one more thing r u getting an error or result is not correct if result is not correct then u can do like

    memset(ky, 0, sizeof(ky));

    or always do allocation with calloc

  5. #5
    and the Hat of Guessing tabstop's Avatar
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    Quote Originally Posted by Jasper View Post
    Nope, I've double checked. I do have #include <string.h> .What's the problem then?Thkc
    If you had string.h at the top of this file (not just somewhere in your code), then you wouldn't be getting this error (you might be "making pointer from integer without a cast" but not the other way around).

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    This has to do with modular decomposition. The code I gave was in the c file. This one below is in the h.file.

    Code:
    typedef struct 
    {
     int id;
     char code;
    }Key;

  7. #7
    and the Hat of Guessing tabstop's Avatar
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    So now you are making a pointer from an integer without a cast, because code is a single character and cannot be used in a string context.

  8. #8
    C++まいる!Cをこわせ! Elysia's Avatar
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    code is a char; it can only hold one character.
    strcpy copies in a string, but you do not have any place to copy that string...
    Quote Originally Posted by Adak View Post
    io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
    Quote Originally Posted by Salem View Post
    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.

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    So.... should I change strcpy(ky->code , keyCode); to ky->code = keyCode; ? Ive tried it but it still gives the same exact error. Thkx

  10. #10
    and the Hat of Guessing tabstop's Avatar
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    You need to change your struct.

  11. #11
    C++まいる!Cをこわせ! Elysia's Avatar
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    You need to make sure there is room in your code member. A string in C is an array of characters.
    Quote Originally Posted by Adak View Post
    io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
    Quote Originally Posted by Salem View Post
    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.

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    Quote Originally Posted by tabstop View Post
    You need to change your struct.

    or change the const char * keyCode to const char keyCode

  13. #13
    C++まいる!Cをこわせ! Elysia's Avatar
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    Neither. You do not seem to understand what they do.
    Quote Originally Posted by Adak View Post
    io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
    Quote Originally Posted by Salem View Post
    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.

  14. #14
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    Elysia, u mean Im supposed to allocate memory for code? If that is so,is the code below the way to do it?
    Code:
     keyCode = (char *) malloc(code * sizeof(char);

  15. #15
    C++まいる!Cをこわせ! Elysia's Avatar
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    keyCode already contains valid memory!
    However, ky->code does not! It contains room for ONE char only. Either you expand it using an array or make it a pointer and allocate using malloc. Only then you have to remember to free it later.
    Quote Originally Posted by Adak View Post
    io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
    Quote Originally Posted by Salem View Post
    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.

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