FILE HANDLING IN C++

FILE HANDLING IN C++

CLASS AND FILE OPERATION:-

#include<fstream>

#include<iostream>

using namespace std;

class student_info

      {

            protected:

                  char name[20];

                  int age;

                  char sex;

                  float height;

                  float weight;

            public:

                  void getdata();

                  void display();

                 

      };

void student_info:: getdata()

      {

     

            cout<<"enter yur name ";

            cout <<" name :";

            cin>> name ;

                  cout<<"enter yur age ";

            cout <<" age :";

            cin>> age ;

                  cout<<"enter yur sex ";

            cout <<" sex :";

            cin>> sex ;

                  cout<<"enter yur height ";

            cout <<" height :";

            cin>> height ;

                  cout<<"enter yur weight ";

            cout <<" weight :";

            cin>> weight ;

           

      }

void student_info::display()

{

      cout<< name<< age<< sex

          << height<< weight<< endl;

}

int main()

{

      student_info o;

      fstream infile;

      char fname[10];

      cout<<"enter a file name";

      cin>> fname;

      infile.open(fname, ios :: in | ios :: out );

      o.getdata();

      infile.open(fname,ios::out);

      cout<<"storing a file";

      infile.write((char*) &o,sizeof(o));

      infile.close();

      // reading file frm a file

      infile.open(fname,ios::in);

      cout<<"reading frm a file..............";

      infile.read((char*) &o,sizeof(o));

      o.display();

      infile.close();

      return 0;

     

}

MERGE TWO FILES INTO ONE FILE:-

#include<iostream>

#include<conio.h>

#include<fstream>

using namespace std;

class emp

{

      int num,age;

      char name[20],dep[5];

      public:

          void getdata()

          {

             cout<<"\n\n  Name   = ";

             cin>>name;

             cout<<"\n Emp Num   = ";

             cin>>num;

             cout<<"\n Department= ";

             cin>>dep;

             cout<<"\n Age       = ";

             cin>>age;

          }

          void display1()

          { 

            cout<<"\n"<<name<<"\t"<<num<<"\t"<<dep<<"\t\t"<<age;

          } 

};

class sal

{

      float gs,ns;

       public:

           void getsal()

           {

             cout<<"\n Gross sal = ";

             cin>>gs;

             cout<<"\n Net sal   = ";

             cin>>ns;

           }

           void display2()

           {

             cout<<"\t"<<gs<<"\t"<<ns;

           }         

};

void display()

{

   emp e;sal s;

   ifstream fil1;

   fil1.open("empdetails.txt",ios::in);

   cout<<"\n\n Name \t Emp Num \t Dep \t Age \t Gross Sal \t Net Sal \n"; 

  while(!fil1.eof())

  {

    fil1.read((char*)&e,sizeof(e));

    e.display1();

    fil1.read((char*)&s,sizeof(s));

    s.display2();

  }  

}

int main()

{

    int n;

    emp e1;sal s1;

    ofstream fil1,fil2,fil3;

    fil1.open("emp.txt",ios::out);

    fil2.open("sal.txt",ios::out);

    fil3.open("empdetails.txt",ios::out);

    cout<<"\n How many employee details do you want to enter = ";

    cin>>n;

    cout<<"\n Enter the deatils one by one \n";

    for(int i=0;i<n;i++)

    {

        e1.getdata();

        fil1.write((char*)&e1,sizeof(e1));

        s1.getsal();

        fil2.write((char*)&s1,sizeof(s1));

        fil3.write((char*)&e1,sizeof(e1));

        fil3.write((char*)&s1,sizeof(s1));

    }

    fil1.close();

    fil2.close();

    fil3.close();

    cout<<"\n\n\t\t Merged file contents \n\n\t\t";

    display();

    getch();

    return 0;

} 

OPEN A BINARY FILE:-

#include<fstream>

#include<iostream>

using namespace std;

int main()

{

      ofstream outfile;

      char fname[10];

      float x,y,temp;

      cout<<" enter a file name";

      cin>>fname;

      outfile.open(fname ,ios::out | ios::binary);

      x=16.5;

      y=10.5;

      cout<<"x    ............ temp"<< endl;

      while(x<=y)

            {

                  temp=x*x;

                  outfile<< x<<'/t'<< temp<< endl;

                  cout<< x   << '/t'<< temp<< endl;

                  x=x+1.5;

            }

      outfile.close();

      return 0;

     

      }

PROGRAMME Q1:-

#include<fstream>

using namespace std;

int main()

{

      ifstream infile;

      infile.open("data.txt");

      cout<<"file has to be opened";

      while((!infile.eof()))

            {

                  ch=infile.get();

                  cout.put(ch);

                 

            }

      infile.close();

      return 0;

}

RANDOM ACCESS:-

#include<iostream>

#include<fstream>

using namespace std;

int main()

{

      fstream infile;

      char fname[20];

      char ch;

      cout<<"enter a name of the file";

      cin >> fname;

      infile.open(fname ,ios::in | ios::out);

      infile.seekg(5l,ios::beg);

      infile.get(ch);

      cout<<" after 5 chr begins........."<<ch;

      cout<<"/n";

      infile.seekg(-10l,ios::end);

      infile.get(ch);

      cout<<" after 10 chr begins........."<<ch;

      cout<<"/n";

      infile.seekg(0,ios::cur);

      infile.get(ch);

      cout<<"  chr begins........."<<ch;

      cout<<"/n";

      infile.close();

      return 0;

}

READ LINES FROM A KEYBOARD:-

// reading a text frm a file and store in a specific file

#include<iostream>

#include<fstream>

using namespace std;

const int MAX = 2000;

int main()

{

      ofstream outfile;

      char fname[10],line[MAX];

      cout<<"enter a file name to opened";

      cin>>fname;

      outfile.open(fname);

      cout<<"enter a set of specific lines end with @\n";

      cin.get(line,MAX,'@');

      cout<<"given input \n";

      cin>>line;

      cout<<"storing in a file";

      outfile<<line;

      outfile.close();

      return 0;

}

STRUCTURE AND FILE OPERATION:-

#include<fstream>

#include<iostream>

using namespace std;

const int MAX =200;

struct school

      {

     

                  char name[20];

                  int age;

                  char sex;

                  float height;

                  float weight;

           

                 

      };

int main()

      {

      struct school student[MAX];

      fstream infile;

      char fname[10];

      int i,n;

      cout<<"enter a file name";

      cin>> fname;

      infile.open(fname, ios :: in | ios :: out );

      cout<<" how  mny record to store";

      cin>>n;

      cout<<"enter the following info";

      for(i=0;i<=n-1;++i)

     

      {

     

            cout<<"enter yur name ";

            cout <<" name :";

            cin>>student[i].name ;

                  cout<<"enter yur age ";

            cout <<" age :";

            cin>> student[i].age ;

                  cout<<"enter yur sex ";

            cout <<" sex :";

            cin>>student[i].sex ;

                  cout<<"enter yur height ";

            cout <<" height :";

            cin>>student[i].height ;

                  cout<<"enter yur weight ";

            cout <<" weight :";

            cin>> student[i].weight ;

           

      }

infile.open(fname,ios::out);

      cout<<"storing a file";

      for(i=0;i<=n-1;++i)

      {

                  infile.write((char*) &student[i],sizeof(student[i]));

      }

      infile.close();

      infile.open(fname,ios::in);

      cout<<"reading frm a file..............";

      for(i=0;i<=n-1;++i)

      {

                  infile.write((char*) &student[i],sizeof(student[i]));

                  cout <<student[i].name <<student[i].age <<student[i].height <<student[i].weight<<student[i].height ;

      }

      infile.close();

      return 0;

}

PROGRAMME:-

#include<fstream>

#include<iostream>

using namespace std;

int main()

{

      ofstream outfile;

      char fname[10];

      float x,y,temp;

      cout<<" enter a file name";

      cin>>fname;

      outfile.open(fname ,ios::out | ios::binary);

      x=16.5;

      y=10.5;

      cout<<"x    ............ temp"<< endl;

      while(x<=y)

            {

                  temp=x*x;

                  outfile<< x<<'/t'<< temp<< endl;

                  cout<< x   << '/t'<< temp<< endl;

                  x=x+1.5;

            }

      outfile.close();

      return 0;

     

      }

WRITE LINE IN A FILE:-

//storing ia textt in a file

#include<iostream>

#include<fstream>

using namespace std;

int main()

{

      ofstream outfile;

      outfile.open("text.dat");

      outfile<<"this is a test program";

      outfile.close();

      return 0;

}

WRITE TO A USER-DEFINED FILE:-

#include<iostream>

#include<fstream>

using namespace std;

int main()

{

      ofstream outfile;

      char fname[10];

      cout<<"enter a name to open a file";

      cin>>fname;

      outfile.open(fname);

      outfile<<"this is a test program";

      outfile<< "program to store a file";

      outfile<<" a set of lines to store in a file";

      outfile.close();

      return 0;

}