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fileHandling guide...

mrprince786 (9)
hi,

I've problem in file handling when i instantiate object thorough fstream ... then file does not open or created... and then through exception my problem close..


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#include"iostream"
#include"fstream"
#include"cstdlib"
#include"ClientData.h"
#include"iomanip"
#include <stdio.h>



using namespace std;

void outputline(ostream&,const ClientData&);


void main(){

	
	
	
int accountNumber;

char lastName[15];
char firstName[10];
double balance;

fstream outCredit;

outCredit.open("credit.txt",ios::out|ios::in|ios::binary);


// problem is here.... file does not open...and then program will exit...

	if(!outCredit)
	{
		cerr<<"file could not be openened."<<endl;
		
		exit(1);

	}
	//outCredit.clear();



cout<<"Enter account number";
ClientData client;

cin>>accountNumber;

while(accountNumber>0 && accountNumber <=100 )
{


	cout<<"enter lastname, firstName and balance value";
	cin>>lastName;
	cin>>firstName;
	cin>>balance;

	client.setAccountNumber(accountNumber);
	client.setLastName(lastName);
	client.setFirstName(firstName);
	client.setBalance(balance);

	outCredit.seekp( (client.getAccountNumber()-1) * sizeof(ClientData) );

	outCredit.write(reinterpret_cast< const char * >(&client),sizeof(ClientData) );

	cout<<"enter accoutn number"<<endl;
	cin>>accountNumber;

}

outCredit.close();

//ClientData obj;

ifstream inCredit("credit.txt",ios::in);


if(!inCredit)
	{
		cerr<<"file could not be openened."<<endl;
		
		exit(1);

	}


inCredit.read(reinterpret_cast<char * >(&client),sizeof(ClientData) );

while(inCredit && !inCredit.eof())
{

	if(client.getAccountNumber()!=0)
		outputline(cout,client);


	inCredit.read(reinterpret_cast<char * >(&client),sizeof(ClientData) );
}


inCredit.close();

//remove("credit.txt");
}

void outputline(ostream &output,const ClientData &record)
{

	output<<left<<setw(10)<<record.getAccountNumber()
		<<setw(16)<<record.getLastName()
		<<setw(11)<<record.getFirstName()
		<<setw(10)<<setprecision(2)<<right<<fixed
		<<showpoint<<record.getBalance()<<endl;




		
}
Last edited on
Galik (2254)
These are wrong:
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#include"iostream"
#include"fstream"
#include"cstdlib"
#include"ClientData.h"
#include"iomanip"
#include <stdio.h>


They should be:

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#include <iostream>
#include <fstream>
#include <cstdlib>
#include "ClientData.h"
#include <iomanip>
#include <cstdio>
mrprince786 (9)
still same error is showing ... on console screen ."file could not be openened."
Galik (2254)
I think because you are opening the file for *reading* as well as writing that the file needs to already exist. I don't think it will create the file for you.
mrprince786 (9)
then what should i do???
RedX (156)
My own experimentation revealed that if you append ios::trunc in the open statement it will create the file but also erase it's contents.
You can check if open succeeded and if not create the file and reopen.
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do{
	outCredit.open("credit.txt",ios::out|ios::in|ios::binary);
	if(!outCredit.is_open()){
		ofstream out("credit.txt",ios::out|ios::binary);
	}
}while(!outCredit.is_open());
Last edited on
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