how to read a binary file data to a monitor
 

Please compare the two codes below why is the first one displaying output to monitor where as the second code is displaying some unwanted characters.

 
CODE 1 .....

#include <fstream.h>

#include <string.h>



void main()

{

        fstream File("test_file.txt",ios::out | ios::in | ios::binary );



        char arr[13];

        strcpy(arr,"Hello World!"); //put Hello World! into the array



        File.write(arr,5); //put the first 5 symbols into the file- "Hello"



        static char read_array[10]; //I will put the read data, here



        File.seekg(ios::beg);

        File.read(read_array,5); //read the first 3 symbols- "Hel"



        cout << read_array << endl; //display them



        File.close();

}



CODE 2....

#include <fstream.h>

#include <string.h>



void main()

{

        fstream File("test_file.txt",ios::out | ios::in | ios::binary );

        char * memblock;

        ifstream::pos_type size;

        //int size;



        File.seekg(ios::ate);

        size = File.tellg();

        memblock = new char[size];

        File.read(memblock,size);



        //cout<<*memblock;

        //cout<<"\n";

        cout<<memblock;

        

        File.close();

}

Re: how to read a binary file data to a monitor
 

CODE 1 may end in problems, too, because of the missing terminating 0 in read_array

CODE 2 is missing a rewind to begin of file before File.read(memblock,size); and has the same problem with the terminating 0. Replace memblock = new char[size]; by memblock = new char[size + 1]; memblock[size] = 0;

Re: how to read a binary file data to a monitor
 

You would also need to delete the memory you've freed, or else you'll get a memory leak

Re: how to read a binary file data to a monitor
 

Both suffer from having void main as well.