File Read

Write char to a file

#include <iostream>
#include <fstream>
using namespace std;

int main(int argc, char *argv[])
{
  char ch;

  if(argc!=2) {
    cout << "Usage: WRITE <filename>\n";
    return 1;
  }

  ofstream out(argv[1], ios::out | ios::binary);

  if(!out) {
    cout << "Cannot open file.\n";
    return 1;
  }

  cout << "Enter a $ to stop\n";
  do {
    cout << ": ";
    cin.get(ch);
    out.put(ch);
  } while (ch!='$');

  out.close();

  return 0;
}

#include <iostream>
#include <fstream>
using namespace std;

int main()
{
  ifstream in("test", ios::in | ios::binary);

  if(!in) {
    cout << "Cannot open input file.\n";
    return 1;
  }

  double num;
  char str[80];

  in.read((char *) &num, sizeof(double));
  in.read(str, 14);
  str[14] = '\0'; // null terminate str

  cout << num << ' ' << str;

  in.close();

  return 0;
}

#include <iostream>
#include <fstream>
using namespace std;

int main()
{ 
  char str[80];

  cout << "Enter your name: ";
  cin.getline(str, 79);

  cout << str << '\n';

  return 0;
}

#include <iostream>
#include <fstream>
#include <cctype>
using namespace std;

int main()
{ 
  char ch;
  ofstream out("test", ios::out | ios::binary);

  if(!out) {
    cout << "Cannot open output file.\n";
    return 1;
  }

  char str[80], *p;
 
  out << 123 << "this is a test" << 23;
  out << "Hello there!" << 99 << "sdf" << endl;
  out.close();
  
  ifstream in("test", ios::in | ios::binary);

  if(!in) {
    cout << "Cannot open input file.\n";
    return 1;
  }

  do {
    p = str;
    ch = in.peek();                    
    if(isdigit(ch)) {
      while(isdigit(*p=in.get())) 
         p++; 
      in.putback(*p); 
      *p = '\0';                        
      cout << "Integer: " << atoi(str);
    }
    else if(isalpha(ch)) {              
      while(isalpha(*p=in.get())) p++;
      in.putback(*p);                   
      *p = '\0';                        
      cout << "String: " << str;
    }
    else 
      in.get();                        
    cout << '\n';
  } while(!in.eof());
  
  in.close();
  return 0;
}