Using Dynamic Object

Dynamic objects expose members such as properties and methods at run time, instead of in at compile time. This enables you to create objects to work with structures that do not match a static type or format. For example, you can use a dynamic object to reference the HTML Document Object Model (DOM), which can contain any combination of valid HTML markup elements and attributes. Because each HTML document is unique, the members for a particular HTML document are determined at run time. A common method to reference an attribute of an HTML element is to pass the name of the attribute to the GetProperty method of the element. To reference the id attribute of the HTML element <div id="Div1">, you first obtain a reference to the <div> element, and then use divElement.GetProperty("id"). If you use a dynamic object, you can reference the id attribute as divElement.id.

Provides a base class for specifying dynamic behavior at run time. This class must be inherited from; you cannot instantiate it directly.

CGI using C++

The Common Gateway Interface (CGI) is a standard protocol for enabling applications (called CGI programs or CGI scripts) to interact with Web servers and with clients. These CGI programs can be a written in Python, PERL, Shell, C or C++ etc.

make sure that your Web Server supports CGI and it is configured to handle CGI Programs. All the CGI Programs to be executed by the HTTP server are kept in a pre-configured directory. This directory is called CGI directory and by convention it is named as /var/www/cgi-bin. By convention CGI files will have extension as .cgi, though they are C++ executable.

By default, Apache Web Server is configured to run CGI programs in /var/www/cgi-bin.


#include <iostream>
using namespace std;

int main ()
{

cout << "Content-type:text/html\r\n\r\n";
cout << "<html>\n";
cout << "<head>\n";
cout << "<title>Hello World - First CGI Program</title>\n";
cout << "</head>\n";
cout << "<body>\n";
cout << "<h2>Hello World! This is my first CGI program</h2>\n";
cout << "</body>\n";
cout << "</html>\n";

return 0;
}


Compile above code and name the executable as cplusplus.cgi. This file is being kept in /var/www/cgi-bin directory and it has following content. Before running your CGI program make sure you have change mode of file using chmod 755 cplusplus.cgi UNIX command to make file executable.

Write then read a text file

This C# code snippet writes a text file from an internal string then reads it back using StreamReader, StreamWriter, TextReader, and TextWriter.
using System;
using System.IO;
 
public class WriteReadClass
{
   public static void Main()
   {
      // write a text file
      TextWriter tws = new StreamWriter ("test.txt");
    
      // write the current datetime to the stream
      tws.WriteLine (DateTime.Now);
    
      // write test strings to the stream
      tws.Write (" Test string 1 to write to file.\n");
      tws.Write (" Test string 2 to write to file.\n");
    
      tws.Close();   // close the stream
 
      // now, read in the text file
      TextReader trs = new StreamReader ("test.txt");
    
      // read the first line of text 
      Console.WriteLine (trs.ReadLine());
 
      // read the rest of the text lines
      Console.WriteLine (trs.ReadToEnd());
    
      trs.Close();   // close the stream
 
      Console.Write ("\nPress \"Enter\" to exit ...");
      Console.Read();
   }
}