Getting an input stream to stop creating a file

This is a discussion on Getting an input stream to stop creating a file within the C++ Programming forums, part of the General Programming Boards category; Hi, Code: #include <fstream.h> ifstream DATABASE_IN; DATABASE_IN.open("afw.raw", ios::in || ios::binary || ios::nocreate); This should open an instream from the binary ...

  1. #1
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    Question Getting an input stream to stop creating a file

    Hi,

    Code:
    #include <fstream.h>
    
    ifstream DATABASE_IN;
    DATABASE_IN.open("afw.raw", ios::in || ios::binary || ios::nocreate);
    This should open an instream from the binary file "afw.raw", if it exists.... but it shouldn't create the file if it doesn't already exist. Lo and behold, everytime I run the program, it has created the file "afw.raw". What am I doing wrong? How can I make sure that the file isn't created?

    Thanks

  2. #2
    Used Registerer jdinger's Avatar
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    You're using a logical OR instead of a bitwise OR. Use just 1: | between the 2nd parameters different values.
    Last edited by jdinger; 03-21-2003 at 02:47 PM.

  3. #3
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    That worked. Thanks.

  4. #4
    Used Registerer jdinger's Avatar
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    No problem. Also, you are using the depricated form of the fstream header. I'd recommend using the newer standard version. With it you don't have to declare ios::nocreate ('nocreate' actually doesn't exist anymore) because if it doesn't exist with ifstreams it won't create it by default.

    Code:
    #include <fstream> //notice no ".h"
    
    int main(void)
    {
       ifstream DATABASE_IN;
       DATABASE_IN.open("afw.raw",ios::binary); //this is all you need
       //all your other stuff here.....
       return(0);
    }

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