Pointers and malloc

This is a discussion on Pointers and malloc within the C Programming forums, part of the General Programming Boards category; Hi, I just have one quick question. I am doing something like this: char *buf = malloc(10); int file_descriptor = ...

  1. #1
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    Pointers and malloc

    Hi, I just have one quick question.
    I am doing something like this:

    char *buf = malloc(10);
    int file_descriptor = ... // just some file descriptor to read from

    read(file_descriptor, buf, 9);

    buf += 5;

    ...

    free(buf);

    Now the question is, when I call free(buf), does it free up all 10 bytes of memory that were allocated? Or only the 5 bytes following the current address that buf is pointing to?

    Thanks.

  2. #2
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    I'm pretty sure that it will free 10 bytes but will free them starting at the point 5 from where you allocated them which could be very bad. But someone should probly confirm that

  3. #3
    Registered User biosx's Avatar
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    Aug 2001
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    230
    It will free any memory allocated with it, so all 10 bytes.

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