Operating system provides macro facility for programmers which allow them to define abbrivation for part of his program.The macro processor treats such definitions as individual code lines and save them as macro definition.So each abbrivation will be actually replaced by their value contents by macro processor.

Macro processor is responsible for substituting all macro calls or macro abbrivations with their macro values.

Open-source software (software with open source code) has become very popular in the last few years and is advancing at a speed unknown outside the world of IT.

Telnet (Telecommunication network) is a network protocol used on the Internet or local area network (LAN) connections. It was developed in 1969 beginning with RFC 15 and standardized as IETF STD 8, one of the first Internet standards. Typically, telnet provides access to a command-line interface on a remote machine.

telnet also refers to software which implements the client part of the protocol. Telnet clients are available for virtually all platforms.

/*Program of queue using array*/
# include
# define MAX 5

int queue_arr[MAX];
int rear = -1;
int front = -1;

main()
{
int choice;
while(1)
{
printf("1.Insert\n");
printf("2.Delete\n");
printf("3.Display\n");
printf("4.Quit\n");
printf("Enter your choice : ");
scanf("%d",&choice);

switch(choice)