i need help with saving file into a binary file

juancarpinteiro (3)
this is my code i don't know why it isn't doing it
#include "stdafx.h"
#include <iostream>
#include <cstring>
#include <string>
#include <iomanip>
#include <stdio.h>
#include "windows.h"
#include <fstream>
using namespace std;

void write_file();
void sort (int n);
void swap(int *p1, int *p2);
void swap2( string *a1, string *a2);
int get_int(int default_value);
void seeWhatsinthearray();
void get_array();
void seeWhatsinthearray2();
void average(int grades[5]);
const int length = 5;
int grades[length];
string names[length];

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int main()
{
	get_array();

	seeWhatsinthearray();//for testing only

	sort(5);

	seeWhatsinthearray2();

	average(grades);

	write_file();

		system("pause");
	return 0;
}
	
	


void get_array() 
{
	char filename[MAX_PATH + 1];
	int n = 0;
	char name[20];
	int grade=0;
	//int age = 0;
	int recsize = sizeof(name) + sizeof(int);
	//int recsize = sizeof(names) + sizeof(int);
	cout << "Enter file name: ";
	cin.getline(filename, MAX_PATH);
	// Open file for binary read-write access.
	fstream fbin(filename, ios::binary | ios::in | ios::out);
	if (!fbin) 
	{
		cout << "Could not open " << filename << endl;
		cout<< "re-enter a valid file: ";
		cin.getline(filename, MAX_PATH);
	}
	// Get record number and go to record.
	cout<< "this is the information on file: " << endl;
	cout<< left << setw(20)<< "name" << setw(4) << "grade" << endl;
	int i=0;
	while(! fbin.eof())
	{
		fbin.seekp(n * recsize);
		// Read data from the file.
		fbin.read(name, sizeof(name) - 1);
		fbin.read((char*)(&grade), sizeof(int));
		cout << endl << left<< setw(20)<< name << setw(4)<< grade << endl;
		grades[i] = grade;
		names[i] = name;
		n++;
		i++;
	}
	fbin.close();
}

void seeWhatsinthearray()
{
	cout << "This is the information in my array: ";
	for(int i=0; i<5; i++)
	{
		cout<< endl << left<< setw(20) << names[i] << setw(4) << grades[i] << endl;
	}
}
void seeWhatsinthearray2()
{
	cout << "This is the information in my array after being sorted: ";
	for(int i=0; i<5; i++)
	{
		cout<< endl << left<< setw(20) << names[i] << setw(4) << grades[i] << endl;
	}
}

int get_int(int default_value) {
	char s[81];
	cin.getline(s, 80);
	if (strlen(s) == 0)
		return default_value;
	return atoi(s);
}
void sort(int x) {
	int i,j, tempnumbers;
	string tempn;

	for (i=0; i<=length; i++)
	{
		for (j=i+1; j<length; j++)
		{
			if (grades[i] > grades[j])
			{ 
				tempnumbers = grades[j];
				grades[j] = grades[i];
				grades[i] = tempnumbers; 

				tempn = names[j];
				names[j] = names[i];
				names[i] = tempn;
			}
		}

	}
}


void average(int grades[5])
{
	int sum=0;
	for (int i=0;i<=5;i++)
	{
		sum = sum + grades[i];
	}
	int avg= sum/5;
	cout<< "this is the average: ";
	cout<< avg <<endl;
	
}






void write_file()
{
	char filename[MAX_PATH + 1];
	int n = 0;
	char name[20];
	int grade=0;
	int recsize = sizeof(name) + sizeof(int);
	cout<< "enter the name of the file for destination: "<< endl;
	cin.getline(filename,MAX_PATH);
	fstream fbin (filename, ios::binary |ios::out);
for (int i=0;i<length;i++)
	{
		fbin.seekp(n * recsize);
		grade= grades[i];
		name = names[i].c_str();
		fbin.write(name,sizeof(names[i])-1);
		fbin.write((char*)(&grade),sizeof(int));
		n++;
	}
	fbin.close();
}



thanks guys
Last edited on
Chervil (812)
You don't say what problem you have exactly.

Here's one line which looks incorrect:
name = names[i].c_str();
should be :
strcpy(name, names[i].c_str());
Make sure array name is large enough to hold the result, or use strncpy()
http://www.cplusplus.com/reference/cstring/strncpy/

On the other hand, why not just do this and forget about the intermediate array:
 
 
        fbin.write(names[i].c_str(), names[i].size() );



Last edited on
juancarpinteiro (3)
omg i'm so thankful to you ............ also for some reason my code doesn't work with the grades. any pointers ?
juancarpinteiro (3)
i fixed the code but still this is my output

Enter file name: e:\wa
this is the information on file:
name grade

S. Long -858993460

A.Smith -858993460

T. Phillip -858993460

J. White -858993460

J. White -858993460

╠╠╠╠♦ -858993460
Press any key to continue . . .\




whats wrong with the writing code for the int array?
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