binaryfiles.cpp

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#include <iostream>
#include <string>
#include <fstream>
using namespace std;
#include "prompt.h"
#include "date.h"

// illustrates reading/writing raw bits, binary files

int main()
{
    string filename = PromptString("file for storing Dates: ");
    int limit =       PromptRange("# of Dates ",10,10000);
	Date today;
    int start = today.Absolute();
    string text = filename + ".txt";
    string binary = filename + ".bin";
	cout << "testing program on " << today << endl;
    
    ofstream toutput(text.c_str());     // open text file
    int k;
    for(k=start; k < start+limit; k++)  // write text form of dates
    {   toutput << Date(k) << endl;
    }
    toutput.close();
    
	// open binary file, write raw dates
    ofstream boutput(binary.c_str(),ios_base::binary);
    for(k=start; k < start+limit; k++)
    {   Date d(k);
        boutput.write(reinterpret_cast<const char *>(&d),sizeof(d));
    }
    boutput.close();
    
	// open input file to read raw dates from
    ifstream input(binary.c_str(),ios_base::binary);
    input.seekg(0,ios_base::beg);     // to the beginning
    streampos startp= input.tellg();  // position of start
    input.seekg(0,ios_base::end);     // seek to end of stream
    streampos endp = input.tellg();   // position of end
    int size = endp-startp;           // number of entries

    cout << "size of file: "  << size << ", # dates = "
		 << size/sizeof(Date) << endl;
    
	// read alldates in file, start at front
    input.seekg(0, ios_base::beg);
    for(k=0; k < size/sizeof(Date); k++)
    {   input.read(reinterpret_cast<char *>(&today),sizeof(today));
		cout << today << endl;
    } 
    return 0;
}