Reading in a binary file

Hey guys,

I'm having a problem reading in a binary file.

Here's my snippet of code I'm trying to work with

Code:

---

#include <iostream>
#include <fstream>
#include <string>

using namespace std;

static unsigned short read_array[25198325];

int main()
{
        //Tag directory of file
        const char *file1 = "/home/my_name/programs/InputFile.ima";

        //Set input file reading
        fstream reader(file1, ios::in | ios::binary);

        if (!reader)
        {
                cout << "\nFile doesn't exist\n" << endl;
                return 0;
        }

        //char ch;
       
        istream &read(read_array, 25198320); 
        //reader.read(read_array, 25198320); 

        return 0;

}

---

I'm trying to get help out of some books and some online help sites, but haven't gotten anywhere with those.
(i.e. I have no idea what I'm doing :p )

So, I'm trying to just read in data from a 50 MB binary file, and to store all the data in the array before I do anything else.

I get this with the code above
error: invalid initialization of non-const reference of
type 'std::istream&' from a temporary of type 'int'

I've tried to change the array to type char, but that hasn't worked either. It really doesn't like that istream &read line. Other than that, the file initialization part seems fine.

Anyone have any ideas? That would help alot :)

Thanks,
Bri Rock

Code:

---

istream &read(read_array, 25198320);

---

I don't like the looks of that! You already have a fstream object right? Well use that to read.

> //reader.read(read_array, 25198320);

Try this:
reader.read(reinterpret_cast<char *> (read_array), 25198320);

Or:
reader.read(reinterpret_cast<char *> (read_array), sizeof(read_array));

Also, you can use gcount() to find out how many bytes were read:

cout << "bytes read: " << reader.gcount() << endl;


EDIT: Changed static_cast to reinterpret_cast. I have no idea what the differences are between static_cast, reinterpret_cast, and dynamic_cast. Except dynamic_cast occurs at runtime perhaps? :confused:

>>50 MB binary file,
>>and to store all the data in the array
That's a fair sized amount of data to read in one go. You'd do better by reading chunks at a time, imho.

Code:

---

#include <iostream>
#include <fstream>
#include <string>

using namespace std;

static unsigned char    read_array[25198325];

int main(void)
{
  const char  *file1 = "junk1.cpp";

  fstream    reader(file1, ios::in | ios::binary);

  if (!reader)
  {
    cout << "\nFile doesn't exist\n" << endl;
    return(0);
  }

  reader.read(read_array, 25198320);
  cout << read_array;
  reader.close();

  return(0);
}

---