Files declaration confusion

This is a discussion on Files declaration confusion within the C Programming forums, part of the General Programming Boards category; Hello. I'm confused about creating a file. I have found two possibilities: 1) FILE *inputFilePtr; inputFilePtr = fopen("afile.txt", "rwb"); Where ...

  1. #1
    Registered User
    Join Date
    Sep 2007
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    38

    Files declaration confusion

    Hello. I'm confused about creating a file. I have found two possibilities:

    1) FILE *inputFilePtr;
    inputFilePtr = fopen("afile.txt", "rwb");

    Where the "r" in the second argument to fopen() opens the file for reading, and the "b" specifies binary mode.

    2) int file;
    char *filename;
    file = open(filename, O_WRONLY|O_CREAT);

    I have been using the second one without problems, but I really want to know difference between boths.
    I believe that both options create a binary file for reading and writing. Please correct if I'm wrong.

    Thanks in advance.

  2. #2
    Kernel hacker
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    The second variety is a "lower level" file-management, and not part of the ANSI standard library. This in turn means that you have to change your code if you for example would like to move it to Windows from Linux.

    Technically, if you want to use open() for read & write, you should specify O_RDWR, and at this level, files don't have any concept of binary or not binary - you get the bytes that are in the file whatever they are.

    --
    Mats
    Compilers can produce warnings - make the compiler programmers happy: Use them!
    Please don't PM me for help - and no, I don't do help over instant messengers.

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