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  1. #1
    Join Date
    Jan 2023
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    2

    adding + 1 with strlen?

    What does the following code do?
    why the code is adding + 1 with strlen?

    Code:
    v4 = (char *)malloc(0x400u);
    
    strlen(v4) + 1;

  2. #2
    Join Date
    Nov 2018
    Posts
    120

    Re: adding + 1 with strlen?

    The +1 is necessary to count the \0 at the end of the string.

    "abc" has a strlen result of 3, but it is stored in memory as "abc\0".

    So if you wanted to allocate space to store "abc", you would need 4 bytes to do it.

  3. #3
    2kaud's Avatar
    2kaud is offline Super Moderator Power Poster
    Join Date
    Dec 2012
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    England
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    Re: adding + 1 with strlen?

    Note that malloc() returns a pointer to uninitialised storage. If the memory pointed to by v4 after malloc() is not initialised before use, it is unknown to what v4 points. Unless v4 memory is initialised between the malloc() and strlen() statements, the result of strlen() is unknown.
    All advice is offered in good faith only. All my code is tested (unless stated explicitly otherwise) with the latest version of Microsoft Visual Studio (using the supported features of the latest standard) and is offered as examples only - not as production quality. I cannot offer advice regarding any other c/c++ compiler/IDE or incompatibilities with VS. You are ultimately responsible for the effects of your programs and the integrity of the machines they run on. Anything I post, code snippets, advice, etc is licensed as Public Domain https://creativecommons.org/publicdomain/zero/1.0/ and can be used without reference or acknowledgement. Also note that I only provide advice and guidance via the forums - and not via private messages!

    C++23 Compiler: Microsoft VS2022 (17.6.5)

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