module11.lst

Programs for the book Advanced Engineering Mathematics using MATLAB, 2ndEd.

listing 1
// Demonstrate a custom inserter. 
 
#include <iostream> 
using namespace std; 
 
class ThreeD { 
public: 
  int x, y, z; // 3-D coordinates 
  ThreeD(int a, int b, int c) { x = a; y = b; z = c; } 
}; 
 
// Display X, Y, Z coordinates - ThreeD inserter. 
ostream &operator<<(ostream &stream, ThreeD obj) 
{ 
  stream << obj.x << ", "; 
  stream << obj.y << ", "; 
  stream << obj.z << "\n"; 
  return stream;  // return the stream 
} 
 
int main() 
{ 
  ThreeD a(1, 2, 3), b(3, 4, 5), c(5, 6, 7); 
 
  cout << a << b << c; 
 
  return 0; 
}

listing 2
// Use a friend to overload <<. 
 
#include <iostream> 
using namespace std; 
 
class ThreeD { 
  int x, y, z; // 3-D coordinates - now private 
public: 
  ThreeD(int a, int b, int c) { x = a; y = b; z = c; } 
  friend ostream &operator<<(ostream &stream, ThreeD obj); 
}; 
 
// Display X, Y, Z coordinates - ThreeD inserter. 
ostream &operator<<(ostream &stream, ThreeD obj) 
{ 
  stream << obj.x << ", "; 
  stream << obj.y << ", "; 
  stream << obj.z << "\n"; 
  return stream;  // return the stream 
} 
 
int main() 
{ 
  ThreeD a(1, 2, 3), b(3, 4, 5), c(5, 6, 7); 
 
  cout << a << b << c; 
 
  return 0; 
}

listing 3
// Demonstrate a custom extractor. 
 
#include <iostream> 
using namespace std; 
 
class ThreeD { 
  int x, y, z; // 3-D coordinates 
public: 
  ThreeD(int a, int b, int c) { x = a; y = b; z = c; } 
  friend ostream &operator<<(ostream &stream, ThreeD obj); 
  friend istream &operator>>(istream &stream, ThreeD &obj); 
} ; 
 
// Display X, Y, Z coordinates - ThreeD inserter. 
ostream &operator<<(ostream &stream, ThreeD obj) 
{ 
  stream << obj.x << ", "; 
  stream << obj.y << ", "; 
  stream << obj.z << "\n"; 
  return stream; // return the stream 
} 
 
// Get three dimensional values - ThreeD extractor. 
istream &operator>>(istream &stream, ThreeD &obj) 
{ 
  cout << "Enter X,Y,Z values: "; 
  stream >> obj.x >> obj.y >> obj.z; 
  return stream; 
} 
 
int main() 
{ 
  ThreeD a(1, 2, 3); 
 
  cout << a; 
 
  cin >> a; 
  cout << a; 
 
  return 0; 
}

listing 4
// Use setf(). 
 
#include <iostream> 
using namespace std; 
 
int main() 
{ 
  // Turn on showpos and scientific flags. 
  cout.setf(ios::showpos); 
  cout.setf(ios::scientific); 
 
  cout << 123 << " " << 123.23 << " "; 
 
  return 0; 
}

listing 5
// Demonstrate flags() and unsetf(). 
 
#include <iostream> 
using namespace std; 
 
int main() 
{ 
  ios::fmtflags f; 
 
  f = cout.flags(); 
 
  if(f & ios::showpos) 
    cout << "showpos is set for cout.\n"; 
  else 
    cout << "showpos is cleared for cout.\n"; 
 
  cout << "\nSetting showpos for cout.\n"; 
  cout.setf(ios::showpos); 
 
  f = cout.flags(); 
 
  if(f & ios::showpos) 
    cout << "showpos is set for cout.\n"; 
  else 
    cout << "showpos is cleared for cout.\n"; 
 
  cout << "\nClearing showpos for cout.\n"; 
  cout.unsetf(ios::showpos); 
 
  f = cout.flags(); 
 
  if(f & ios::showpos) 
    cout << "showpos is set for cout.\n"; 
  else 
    cout << "showpos is cleared for cout.\n"; 
 
  return 0; 
} 


listing 6
// Demonstrate width(), precision(), and fill(). 
 
#include <iostream> 
using namespace std; 
 
int main() 
{ 
  cout.setf(ios::showpos); 
  cout.setf(ios::scientific); 
  cout << 123 << " " << 123.23 << "\n"; 
 
  cout.precision(2); // two digits after decimal point 
  cout.width(10);    // in a field of 10 characters 
  cout << 123 << " "; 
  cout.width(10);    // set width to 10 
  cout << 123.23 << "\n"; 
 
  cout.fill('#');  // fill using # 
  cout.width(10);  // in a field of 10 characters 
  cout << 123 << " "; 
  cout.width(10);  // set width to 10 
  cout << 123.23; 
 
  return 0; 
}

listing 7
// Demonstrate an I/O manipulator. 
 
#include <iostream> 
#include <iomanip> 
using namespace std; 
 
int main() 
{ 
  cout << setprecision(2) << 1000.243 << endl; 
  cout << setw(20) << "Hello there."; 
 
  return 0; 
}

listing 8
// Use setiosflags(). 
 
#include <iostream> 
#include <iomanip> 
using namespace std; 
 
int main() 
{ 
  cout << setiosflags(ios::showpos) << 
          setiosflags(ios::scientific) << 
          123 << " " << 123.23; 
 
  return 0; 
}

listing 9
// Skip leading whitespace. 
 
#include <iostream> 
using namespace std; 
 
int main() 
{ 
  char s[80]; 
 
  cin >> ws >> s; 
  cout << s; 
 
  return 0; 
}

listing 10
// Create an output manipulator. 
 
#include <iostream> 
#include <iomanip> 
using namespace std; 
 
ostream &setup(ostream &stream) 
{ 
  stream.setf(ios::left); 
  stream << setw(10) << setfill('$'); 
  return stream; 
} 
 
int main() 
{ 
  cout << 10 << " " << setup << 10; 
 
  return 0; 
}

listing 11
// Create an input manipulator. 
 
#include <iostream> 
#include <iomanip> 
using namespace std; 
 
istream &prompt(istream &stream) 
{ 
  cin >> hex; 
  cout << "Enter number using hex format: "; 
 
  return stream; 
} 
 
int main() 
{ 
  int i; 
 
  cin >> prompt >> i; 
  cout << i; 
 
  return 0; 
}

listing 12
// Write to file. 
 
#include <iostream> 
#include <fstream> 
using namespace std; 
 
int main() 
{ 
  ofstream out("test"); 
  if(!out) { 
    cout << "Cannot open file.\n"; 
    return 1; 
   } 
 
  out << 10 << " " << 123.23 << "\n"; 
  out << "This is a short text file."; 
 
  out.close(); 
 
  return 0; 
}

listing 13
// Read from file. 
 
#include <iostream> 
#include <fstream> 
using namespace std; 
 
int main() 
{ 
  char ch; 
  int i; 
  float f; 
  char str[80]; 
 
  ifstream in("test"); 
  if(!in) { 
    cout << "Cannot open file.\n"; 
    return 1; 
  } 
 
  in >> i; 
  in >> f; 
  in >> ch; 
  in >> str; 
 
  cout << i << " " << f << " " << ch << "\n"; 
  cout << str; 
 
  in.close(); 
  return 0; 
}

listing 14
// Display a file using get(). 
 
#include <iostream> 
#include <fstream> 
using namespace std; 
 
int main(int argc, char *argv[]) 
{ 
  char ch; 
 
  if(argc!=2) { 
    cout << "Usage: PR <filename>\n"; 
    return 1; 
  } 
 
  ifstream in(argv[1], ios::in | ios::binary); 
  if(!in) { 
    cout << "Cannot open file.\n"; 
    return 1; 
  } 
 
  while(in) { // in will be false when eof is reached 
    in.get(ch); 
    if(in) cout << ch; 
  } 
 
  in.close(); 
 
  return 0; 
}

listing 15
// Use put() to write to a file. 
 
#include <iostream> 
#include <fstream> 
using namespace std; 
 
int main() 
{ 
  char *p = "hello there\n"; 
 
  ofstream out("test", ios::out | ios::binary); 
  if(!out) { 
    cout << "Cannot open file.\n"; 
    return 1; 
   } 
 
  // Write characters until the null-terminator is reached. 
  while(*p) out.put(*p++); 
 
  out.close(); 
 
  return 0; 
}

listing 16
// Use read() and write(). 
 
#include <iostream> 
#include <fstream> 
using namespace std; 
 
int main() 
{ 
  int n[5] = {1, 2, 3, 4, 5}; 
  register int i; 
 
  ofstream out("test", ios::out | ios::binary); 
  if(!out) { 
    cout << "Cannot open file.\n"; 
    return 1; 
   } 
 
  out.write((char *) &n, sizeof n); 
 
  out.close(); 
 
  for(i=0; i<5; i++) // clear array 
    n[i] = 0; 
 
  ifstream in("test", ios::in | ios::binary); 
  if(!in) { 
    cout << "Cannot open file.\n"; 
    return 1; 
  } 
 
  in.read((char *) &n, sizeof n); 
 
  for(i=0; i<5; i++) // show values read from file 
    cout << n[i] << " "; 
 
  in.close(); 
 
  return 0; 
}

listing 17
// Use get() to read a string that contains spaces. 
 
#include <iostream> 
#include <fstream> 
using namespace std; 
 
int main() 
{ 
  char str[80]; 
 
  cout << "Enter your name: "; 
  cin.get(str, 79); 
 
  cout << str << '\n'; 
 
  return 0; 
}

listing 18
/*   
   Project 11-1   
  
   Create a file comparision utility.   
*/   
   
#include <iostream>  
#include <fstream>  
using namespace std;  
  
int main(int argc, char *argv[])  
{  
  register int i;  
  int numread;  
  
  unsigned char buf1[1024], buf2[1024];  
  
  if(argc!=3) {  
    cout << "Usage: compfiles <file1> <file2>\n";  
    return 1;  
  }  
  
  ifstream f1(argv[1], ios::in | ios::binary);  
  if(!f1) {  
    cout << "Cannot open first file.\n";  
    return 1;  
  }  
  ifstream f2(argv[2], ios::in | ios::binary);  
  if(!f2) {  
    cout << "Cannot open second file.\n";  
    return 1;  
   }  
  
  cout << "Comparing files...\n";  
  
  do {  
    f1.read((char *) buf1, sizeof buf1);  
    f2.read((char *) buf2, sizeof buf2);  
 
    if(f1.gcount() != f2.gcount()) { 
      cout << "Files are of differing sizes.\n"; 
      f1.close();  
      f2.close();  
      return 0; 
    } 
 
    // compare contents of buffers  
    for(i=0; i<f1.gcount(); i++)  
      if(buf1[i] != buf2[i]) {  
        cout << "Files differ.\n";  
        f1.close();  
        f2.close();  
        return 0;  
      }  
  
  } while(!f1.eof() && !f2.eof());  
  
  cout << "Files are the same.\n";  
  
  f1.close();  
  f2.close();  
  
  return 0;  
}

listing 19
// Demonstrate random access. 
 
#include <iostream> 
#include <fstream> 
#include <cstdlib> 
using namespace std; 
 
int main(int argc, char *argv[]) 
{ 
  if(argc!=3) { 
    cout << "Usage: CHANGE <filename> <byte>\n"; 
    return 1; 
  } 
 
  fstream out(argv[1], ios::in | ios::out | ios::binary); 
  if(!out) { 
    cout << "Cannot open file.\n"; 
    return 1; 
  } 
 
  out.seekp(atoi(argv[2]), ios::beg); 
 
  out.put('X'); 
  out.close(); 
 
  return 0; 
}

listing 20
// Display a file from a given starting point. 
 
#include <iostream> 
#include <fstream> 
#include <cstdlib> 
using namespace std; 
 
int main(int argc, char *argv[]) 
{ 
  char ch; 
 
  if(argc!=3) { 
    cout << "Usage: NAME <filename> <starting location>\n"; 
    return 1; 
  } 
 
  ifstream in(argv[1], ios::in | ios::binary); 
  if(!in) { 
    cout << "Cannot open file.\n"; 
    return 1; 
  } 
 
  in.seekg(atoi(argv[2]), ios::beg); 
 
  while(in.get(ch)) 
    cout << ch; 
 
  return 0; 
}