server.c

/*
 * Title : Full duplex server side 
 * Name : Aditya Pratap Singh Rajput
 * Subject : Network Protocols And Programming using C
 * 
Note : please consider the TYPOS in comments.
Thanks.
*/

#include<sys/types.h>
#include<sys/socket.h>
#include<stdio.h>
#include<unistd.h>
#include<netdb.h>
#include<arpa/inet.h>
#include<netinet/in.h>
#include<string.h>

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

struct sockaddr_in serverAddress,clientAddress;
socklen_t clientLength;

char recvBuffer[1000],sendBuffer[1000];
pid_t cpid;
bzero(&serverAddress,sizeof(serverAddress));
/*Socket address structure*/
serverAddress.sin_family=AF_INET;
serverAddress.sin_addr.s_addr=htonl(INADDR_ANY);
serverAddress.sin_port=htons(5500);
/*TCP socket is created, an Internet socket address structure is filled with
wildcard address & server’s well known port*/
socketDescriptor=socket(AF_INET,SOCK_STREAM,0);
/*Bind function assigns a local protocol address to the socket*/
bind(socketDescriptor,(struct sockaddr*)&serverAddress,sizeof(serverAddress));
/*Listen function specifies the maximum number of connections that kernel should queue
for this socket*/
listen(socketDescriptor,5);
printf("%s\n","Server is running ...");
/*The server to return the next completed connection from the front of the
completed connection Queue calls it*/
clientSocketDescriptor=accept(socketDescriptor,(struct sockaddr*)&clientAddress,&clientLength);
/*Fork system call is used to create a new process*/
cpid=fork();

if(cpid==0)
{
while(1)
{
bzero(&recvBuffer,sizeof(recvBuffer));
/*Receiving the request from client*/
recv(clientSocketDescriptor,recvBuffer,sizeof(recvBuffer),0);
printf("\nCLIENT : %s\n",recvBuffer);
}
}
else
{
while(1)
{

bzero(&sendBuffer,sizeof(sendBuffer));
printf("\nType a message here ...  ");
/*Read the message from client*/
fgets(sendBuffer,10000,stdin);
/*Sends the message to client*/
send(clientSocketDescriptor,sendBuffer,strlen(sendBuffer)+1,0);
printf("\nMessage sent !\n");
}
}
return 0;
}