Quick Realloc question

This is a discussion on Quick Realloc question within the C Programming forums, part of the General Programming Boards category; Code: strucType makeBigger(structType x, char ch) { /* Struct x was previous malloc to 8 bits*/ x = realloc(x, 100); ...

  1. #1
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    Quick Realloc question

    Code:
    strucType makeBigger(structType  x, char ch)
    { /* Struct x was previous malloc to 8 bits*/ 
       x = realloc(x, 100); 
       printf("%d", sizeof(x));
    }
    So this should print out 100, but it keeps printing out 8.. I know its something to do with pointers but I have nooo idea what. Have added *'s and &'s infront of the x's and nothing is working. Any help would be really appreciated :-)

  2. #2
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    It prints 8 because you are asking for the size of the pointer (x).

    You can't actually print out the size of a block of allocated memory. You have to track that for yourself.

  3. #3
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    Oh!!! Ok, that makes sense... Thanks so much!

  4. #4
    ATH0 quzah's Avatar
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    Quote Originally Posted by Sonny Trujillo View Post
    Code:
    strucType makeBigger(structType  x, char ch)
    { /* Struct x was previous malloc to 8 bits*/ 
       x = realloc(x, 100); 
       printf("%d", sizeof(x));
    }
    What happens to x when realloc fails?


    Quzah.
    Hope is the first step on the road to disappointment.

  5. #5
    Algorithm Dissector iMalc's Avatar
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    Which is precisely why I recommend that people do not use realloc.
    Virtually all of those who start threads on here and have code that includes realloc are using it wrong.
    My homepage
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