* Write a program to read a text file and display its contents on the screen.

#+ATTR_LATEX: :options frame=single,breaklines=true
#+begin_src cpp :tangle 28.cpp :wrap src text
#include <fstream>
#include <iostream>

using namespace std;
const string FILE_PATH = "./28.in";

int main() {
  string line;

  fstream file;
  file.open(FILE_PATH, ios_base::in);

  if (!file.is_open())
    exit(1);

  while (getline(file, line)) {
    cout << line;
    if (file.peek() != EOF) {
      cout << endl;
    }
  }

  file.close();

  return 0;
}
#+end_src

#+begin_src text
Asperger syndrome (AS), also known as Asperger's, is a former neurodevelopmental disorder.
It is characterized by significant difficulties in social interaction and nonverbal communication.
#+end_src

#+LATEX: \clearpage

* Write a program to copy the contents of a file into another.

#+ATTR_LATEX: :options frame=single,breaklines=true
#+begin_src cpp :tangle 29.cpp :wrap src text
#include <fstream>
#include <iostream>

using namespace std;
const string SRC_FILE_PATH = "./29.in";
const string DST_FILE_PATH = "./29.out";

int main() {
  string line;

  fstream src, dst;
  src.open(SRC_FILE_PATH, ios_base::in);
  dst.open(DST_FILE_PATH, ios_base::out);
  dst.close();
  dst.open(DST_FILE_PATH, ios_base::app);

  if (!src.is_open())
    exit(1);

  while (getline(src, line)) {
    dst << line;
    if (src.peek() != EOF) {
      dst << endl;
    }
  }

  src.close();
  dst.close();

  return 0;
}
#+end_src

#+LATEX: \clearpage

* Write a program to read the class object of student_info such as name , age ,sex ,height and weight from the keyboard and to store them on a specified file using read() and write() functions. Again the same file is opened for reading and displaying the contents of the file on the screen.

#+ATTR_LATEX: :options frame=single,breaklines=true
#+begin_src cpp :tangle 30.cpp :wrap src text
#include <fstream>
#include <iostream>
#include <ostream>

using namespace std;
const string FILE_PATH = "./30.out";

class StudentInfo {
  char name[30];
  uint age;
  char sex;
  uint height;
public:
  void read();
  void write();
};

void StudentInfo::read() {
  cout << "Name: ";
  cin >> name;
  cout << "Age: ";
  cin >> age;
  cout << "Sex (m/f): ";
  cin >> sex;
  cout << "Height: ";
  cin >> height;
  cout << "[LOG] Data read\n";
}

void StudentInfo::write() {
  ofstream file(FILE_PATH);
  file.close();
  file.open(FILE_PATH, ios_base::app);

  file << "Name: " << name << endl
       << "Age: " << age << endl
       << "Sex: " << (sex == 'm' ? "Male" : "Female") << endl
       << "Height: " << height << "cm";

  cout << "[LOG] Data written\n";

  file.close();
}

int main() {
  StudentInfo foo;
  string line;

  foo.read();
  foo.write();

  ifstream file(FILE_PATH);

  if (!file.is_open())
    exit(1);

  cout << "File contents: \n";
  
  while (getline(file, line)) {
    cout << line;
    if (file.peek() != EOF) {
      cout << endl;
    }
  }

  return 0;
}
#+end_src

#+begin_src text
Name: Hello
Age: 19
Sex (m/f): m
Height: 180
[LOG] Data read
[LOG] Data written
File contents: 
Name: Hello
Age: 19
Sex: Male
Height: 180cm
#+end_src