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#include <iostream>
#include <fstream>
using namespace std;
struct Student
{
char* name;
int fn;
int gradesCount;
double averageGrade;
};
void print(const Student& st)
{
cout << st.name << " " << st.fn << " " << st.gradesCount << " " << st.averageGrade << endl;
}
Student createStudent(const char* name, int fn, int gradesCount, double avGrade)
{
Student obj;
size_t nameLen = strlen(name);
obj.name = new char[nameLen + 1];
strcpy(obj.name, name);
obj.fn = fn;
obj.gradesCount = gradesCount;
obj.averageGrade = avGrade;
return obj;
}
void saveStudentToFile(ofstream& f, const Student& st)
{
size_t nameLen = strlen(st.name);
f.write((const char*)&nameLen, sizeof(nameLen)); //first we write the size of the name!
f.write(st.name, nameLen);
f.write((const char*)&st.fn, sizeof(st.fn));
f.write((const char*)&st.gradesCount, sizeof(st.gradesCount));
f.write((const char*)&st.averageGrade, sizeof(st.averageGrade));
}
Student readStudentFromFile(ifstream& f)
{
Student res;
size_t nameLen;
f.read((char *)&nameLen, sizeof(nameLen)); //first we read the size of the name!
res.name = new char[nameLen + 1];
f.read(res.name, nameLen);
res.name[nameLen] = '\0';
f.read((char *)&res.fn, sizeof(res.fn));
f.read((char*)&res.gradesCount, sizeof(res.gradesCount));
f.read((char*)&res.averageGrade, sizeof(res.averageGrade));
return res;
}
void freeStudent(Student& s)
{
delete[] s.name;
s.averageGrade = s.fn = s.gradesCount = 0;
}
int main()
{
{ //save students to file
Student s1 = createStudent("Ivan", 1234, 2, 4);
Student s2 = createStudent("Petur", 5555, 5, 5.5);
ofstream f1("uni.dat", ios::binary);
if (!f1.is_open())
{
cout << "Error" << endl;
return -1;
}
saveStudentToFile(f1, s1);
saveStudentToFile(f1, s2);
freeStudent(s1);
freeStudent(s2);
f1.close();
}
{ //read students from file
ifstream f2("uni.dat", ios::binary);
if (!f2.is_open())
{
cout << "Error" << endl;
return -1;
}
Student s1 = readStudentFromFile(f2);
Student s2 = readStudentFromFile(f2);
print(s1);
print(s2);
freeStudent(s1);
freeStudent(s2);
f2.close();
}
}
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