Can't able to read the binary file [closed] - c++

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// STRUCTURE FOR ADD NEW DRIVER'S RECORD
struct driver
{
int long reg;
string name;
string fhname;
string peraddress;
string pesentaddress;
string dob;
string cnic;
string qualification;
string occupation;
string phone;
string mobile;
string licnum;
string email;
string city;
string gender;
string province;
string lictype;
string vitype;
}e[100];
// FUNCTION FOR ADD NEW RECORD OF DRIVER
void add_driver_record()
{
system("CLS");
char option;
fstream driverTextFile, addrecord;
addrecord.open("rcd.data", ios::out | ios::app | ios::binary);
cout << "Do you Want to Enter New Record (Y/N) ";
option = _getch();
system("cls");
if (option == 'Y' || option == 'y')
{
for (int i = 1; i == 1; i++)
{
while (option != 'N')
{
cout << "\t\t Driver Information " << endl;
cout << "\t\t++++++++++++++++++++" << endl;
cout << "\t\tEnter Token No :";
cin >> e[i].reg;
cout << "\t\tEnter License Number :";
cin.ignore();
getline(cin, e[i].licnum);
cout << "\t\tEnter Full Name :";
getline(cin, e[i].name);
cout << "\t\tEnter Father/Husband Name :";
getline(cin, e[i].fhname);
cout << "\t\tEnter Permanent Address :";
getline(cin, e[i].peraddress);
cout << "\t\tEnter Present Address :";
getline(cin, e[i].pesentaddress);
cout << "\t\tEnter Date of Birth :";
getline(cin, e[i].dob);
cout << "\t\tEnter CNI :";
getline(cin, e[i].cnic);
cout << "\t\tEnter city :";
getline(cin, e[i].city);
cout << "\t\tEnter Province :";
getline(cin, e[i].province);
cout << "\t\tEnter Gender :";
cin >> e[i].gender;
cout << "\t\tEnter Occupation :";
cin >> e[i].occupation;
cout << "\t\tEnter Qaulification :";
cin.ignore();
getline(cin, e[i].qualification);
cout << "\t\tEnter E-mail :";
cin.ignore();
getline(cin, e[i].email);
cout << "\t\tEnter Phone No :";
cin >> e[i].phone;
cout << "\t\tEnter Mobile No :";
cin >> e[i].mobile;
cout << "\t\tEnter License Type :";
cin.ignore();
getline(cin, e[i].lictype);
cout << "\t\tEnter Vehicle Type :";
cin.ignore();
getline(cin, e[i].vitype);
addrecord.write((char *)&e, sizeof(driver));
driverTextFile << "========================================================\n";
driverTextFile << "\t\t Driver Information " << endl;
driverTextFile << "\t\t+++++++++++++++++++++++" << endl;
driverTextFile << "\t\t Token No :" << e[i].reg << endl;
driverTextFile << "\t\t License Number :" << e[i].licnum << endl;
driverTextFile << "\t\t Full Name :" << e[i].name << endl;
driverTextFile << "\t\t Father/Husband Name :" << e[i].fhname << endl;
driverTextFile << "\t\t Permanent Address :" << e[i].peraddress << endl;
driverTextFile << "\t\t Present Address :" << e[i].pesentaddress << endl;
driverTextFile << "\t\t Date of Birth :" << e[i].dob << endl;
driverTextFile << "\t\t CNIC :" << e[i].cnic << endl;
driverTextFile << "\t\t City :" << e[i].city << endl;
driverTextFile << "\t\t Province :" << e[i].province << endl;
driverTextFile << "\t\t Gender :" << e[i].gender << endl;
driverTextFile << "\t\t Occupation :" << e[i].occupation << endl;
driverTextFile << "\t\t Qaulification :" << e[i].qualification << endl;
driverTextFile << "\t\t E-mail :" << e[i].email << endl;
driverTextFile << "\t\t Phone No :" << e[i].phone << endl;
driverTextFile << "\t\t Mobile No :" << e[i].mobile << endl;
driverTextFile << "\t\t Enter License Type :" << e[i].lictype << endl;
driverTextFile << "\t\t Enter Vehicle Type :" << e[i].vitype << endl;
driverTextFile << "========================================================\n";
addrecord.close();
cout << "Do you Want to Enter New Record (Y/N) ";
cin >> option;
switch (option) {
case 'Y':
case 'y':
add_driver_record();
break;
case 'N':
case 'n':
exit(1);
break;
default:
printf("Please select suitable option \n");
add_driver_record();
break;
}
} // while Loop ends
}// for loop ends
} // if condition ends
else if (option == 'N' || option == 'n')
{
printf("Please Select Suitable Option \n");
}
}
// FUNCTION FOR DISPLAY ALL RECORDS OF DRIVER'S
void display_all_driver()
{
system("CLS");
system("color f5");
fstream myfile, driverTextFile;
myfile.open("rcd.data", ios::in | ios::out | ios::binary);
int idx = 1;
while (idx == 1)
{
myfile.read((char*)&e[idx].reg, sizeof(e[idx].reg));
myfile.read((char*)&e[idx].licnum, sizeof(e[idx].licnum));
myfile.read((char*)&e[idx].name, sizeof(e[idx].name));
myfile.read((char*)&e[idx].fhname, sizeof(e[idx].fhname));
myfile.read((char*)&e[idx].peraddress, sizeof(e[idx].peraddress));
myfile.read((char*)&e[idx].pesentaddress, sizeof(e[idx].pesentaddress));
myfile.read((char*)&e[idx].dob, sizeof(e[idx].dob));
myfile.read((char*)&e[idx].cnic, sizeof(e[idx].cnic));
myfile.read((char*)&e[idx].city, sizeof(e[idx].city));
myfile.read((char*)&e[idx].province, sizeof(e[idx].province));
myfile.read((char*)&e[idx].gender, sizeof(e[idx].gender));
myfile.read((char*)&e[idx].occupation, sizeof(e[idx].occupation));
myfile.read((char*)&e[idx].qualification, sizeof(e[idx].qualification));
myfile.read((char*)&e[idx].email, sizeof(e[idx].email));
myfile.read((char*)&e[idx].phone, sizeof(e[idx].phone));
myfile.read((char*)&e[idx].mobile, sizeof(e[idx].mobile));
myfile.read((char*)&e[idx].lictype, sizeof(e[idx].lictype));
myfile.read((char*)&e[idx].vitype, sizeof(e[idx].vitype));
cout << "========================================================\n";
cout << "\t\t Driver Information " << endl;
cout << "\t\t+++++++++++++++++++++++" << endl;
cout << "\t\t Token No :" << e[idx].reg << endl;
cout << "\t\t License Number :" << e[idx].licnum << endl;
cout << "\t\t Full Name :" << e[idx].name << endl;
cout << "\t\t Father/Husband Name :" << e[idx].fhname << endl;
cout << "\t\t Permanent Address :" << e[idx].peraddress << endl;
cout << "\t\t Present Address :" << e[idx].pesentaddress << endl;
cout << "\t\t Date of Birth :" << e[idx].dob << endl;
cout << "\t\t CNIC :" << e[idx].cnic << endl;
cout << "\t\t City :" << e[idx].city << endl;
cout << "\t\t Province :" << e[idx].province << endl;
cout << "\t\t Gender :" << e[idx].gender << endl;
cout << "\t\t Occupation :" << e[idx].occupation << endl;
cout << "\t\t Qaulification :" << e[idx].qualification << endl;
cout << "\t\t E-mail :" << e[idx].email << endl;
cout << "\t\t Phone No :" << e[idx].phone << endl;
cout << "\t\t Mobile No :" << e[idx].mobile << endl;
cout << "\t\t Enter License Type :" << e[idx].lictype << endl;
cout << "\t\t Enter Vehicle Type :" << e[idx].vitype << endl;
cout << "========================================================\n";
idx++;
}
myfile.close();
}
I am so sorry if somebody else had already asked this question. But I am unable to rectify the problem that I "can not" read the binary file on console. Let me tell what my code is doing. I took structure with bunch of attribute and taking the input in that and saving that data in Binary file. And i want to read that in second method. But I am completely unable to read the data. This is my code please provide me solution. I have already tried several ways but I am still unable. Your help will save me semester project.

Answer 1

Your struct driver consists of std::strings, which internally represent the actual content trough a pointer to dynamically allocated memory. When you write such a struct (or an array of such structs) as plain bytes to a file, you actually write out "memory addresses" and not the actual content of the strings. So you will loose the actual content, and reading in the file will give you plain garbage.
Try the following program illustrating this:
struct TestStruct {
string testString;
};
int main(){
TestStruct ts;
cout << "sizeof ts with empty string: " << sizeof(ts) << endl;
ts.testString = "Will not get larger, right?";
cout << "sizeof ts with string set to some content: " << sizeof(ts) << endl;
}
Output:
sizeof ts with empty string: 24
sizeof ts with string set to some content: 24

Answer 2

Do you have read permissions for the file? That is my first thought that it is a permissions issue.