The \nocite Command in BibTeX

  The normal behavior of BibTeX is set in such a way that unreferenced entries in the .bib file will not be displayed in the bibliography section. But what if we need to print even the unreferenced entries in the .bib file also made part of the bibliographic section? For that we have a command called \nocite{*}. This command will override the default behavior of BibTeX such that even an referenced entries in the .bib file will be added in the bibliographic section in the DVI or PDF file produced. The script below shows the working of \nocite{*} command. The TeX file uses a .bib file called bib1.bib. 

\documentclass{article}

\usepackage{natbib}

\title{Sample Article}

\author{D}

\begin{document}

\maketitle

\nocite{*}

Here the entries in the Bibfile are not referenced. 

But they are shown in the reference section because we 

use \textbackslash cite\{*\} command.

\bibliographystyle{plain}

\bibliography{bib1.bib}

\end{document}

Client Server Program in C to Simulate TCP Multicast Server

  This program simulates a multicast server in C. The following line of code sets the number of clients accepted by the server program. 

#define NC 4

Here the number of clients is set as 4. First run the server process, then run the client processes.

Click here to download the Client program.

Clcik here to download the Server Program.

Client Server Program in C to Simulate Go-Back-N-ARQ

  This program was also written some 5 years before. This again is a simulation program trying to imitate Go-Back-N ARQ. It is a client server program. Click here to view the Wikipedia article on Go-Back-N_ARQ. Here also the server side acts as the receiver and hence you should run this program first. Afterwards you should also run the client program which acts as the sender side. 

Figure Below Shows the Receiver

Figure Below Shows the Sender

The line given below sets the window size for the sender and the receiver.

#define W 5 
If you want you can change the window size to some other value. Currently the window size is 5.

The following lines in the receiver side decides the probability with which a frame fails to reach the destination.

#define P1 50
#define P2 10

You can increase the probability of a frame being corrupted by increasing the value of P2 and decrease the probability by decreasing the value of P2. Currently there is a 20% probability for frame corruption.

Click here to download the Receiver Side program.

Click here to download the Sender Side program.


Click here to view the article on Selective Repeat ARQ.

Client Server Program in C to Simulate Selective Repeat ARQ

  I wrote these programs 5 years ago. It is a simulation program trying to imitate the working of Selective Repeat ARQ. Click here to view the Wikipedia article on Selective Repeat ARQ. A client server C program is used to simulate the working of Selective Repeat ARQ. The server acts as the receiver. The client acts as the sender. Because of this reason first run the receiver program and afterwards run the sender program. 

Figure Below Shows theReceiver

Figure Below Shows the Sender

  

The line given below sets the window size for the sender and the receiver.

#define W 5 
If you want you can change the window size to some other value. Currently the window size is 5.

The following lines in the receiver side decides the probability with which a frame fails to reach the destination.

#define P1 50
#define P2 10

You can increase the probability of a frame being corrupted by increasing the value of P2 and decrease the probability by decreasing the value of P2. Currently there is a 20% probability for frame corruption.

Click here to download the Receiver Side program. 

Click here to download the Sender Side program. 


Click here to view the article on Go-Back-N ARQ.

In C and C++ typedef is a Storage Class Specifier

  Consider the program given below.

#include<stdio.h>
int main()
{
   typedef static int i;
   i a = 0;
   printf("%d", a);
   return 0;
}

The program when compiled as C or C++ will give you the following error "multiple storage classes in declaration specifiers". The error tells us that typedef in C and C++ is treated as a storage class specifier and this leads to the error since it is not allowed to use two storage class specifiers with a variable.

The C Reference Manual says "The typedef specifier does not reserve storage and is called a storage class specifier only for syntactic convenience".

Yet Another Difference Between C and C++: Initializing Constant Variables

  Constant variable initialization is yet another minute difference between C and C++. Consider the program given below.

#include<stdio.h>
int main()
{
  int x = 111;
  static int y = x;
  if(x == y)
     printf("Equal");
  else
     printf("Not Equal");
  return 0;
}

If you save the program as a C++ program, it compiles fine and shows the output as "Equal". But the same program when compiled as C will give you the following error "initializer element is not constant|". What is the reason? This is another minor difference between C and C++. In C a constant variable can only be initialized with a constant value and not by using another variable. But C++ do not have this restriction. You can initialize a constant variable with any other variable.

Click here to download the C++ program.

Yet Another Difference Between C and C++: Case Labels

 There are many major differences between C and C++. Such differences are matters for Text Books and Manuals. Here I am pointing out yet another minor difference between C and C++. This time the difference arises from the way case labels are treated in C and C++. 

 C++ will allow const int variables as case labels, whereas C will give you an error. Consider the program given below.

#include<stdio.h>

int main()
{
    int i=1;
    const int j=1;
    switch(i)
    {
        case j:
            printf("\nHello\n\n");
            break;
        case 2:
            printf("\nHi\n\n");
            break;
        default:
            printf("\nWelcome\n\n");
    }
    return 0;
}

The program will give the error 'case label does not reduce to an integer constant' when compiled as a C program. But when compiled as a C++ program the program executes without any errors and gives 'Hello' as output.