server.c

#include<string.h>
#include<unistd.h>
#include<sys/socket.h>
#include<sys/types.h>
#include<netinet/in.h>
#include<stdlib.h>
#include<stdio.h>

int main()
{
	int s,r,recb,sntb,x,ns,a=0;
	printf("INPUT port number: ");
	scanf("%d", &x);
	socklen_t len;
	struct sockaddr_in server,client;
	char buff[50],buff2[50];

	s=socket(AF_INET,SOCK_STREAM,0);
	if(s==-1)
	{
		printf("\nSocket creation error.");
		exit(0);
	}
	printf("\nSocket created.");

	server.sin_family=AF_INET;
	server.sin_port=htons(x);
	server.sin_addr.s_addr=htonl(INADDR_ANY);

	r=bind(s,(struct sockaddr*)&server,sizeof(server));
	if(r==-1)
	{
		printf("\nBinding error.");
		exit(0);
	}
	printf("\nSocket binded.");

	r=listen(s,1);
	if(r==-1)
	{
		close(s);
		exit(0);
	}
	printf("\nSocket listening.");

	len=sizeof(client);

	ns=accept(s,(struct sockaddr*)&client, &len);
	if(ns==-1)
	{
		close(s);
		exit(0);
	}
	printf("\nSocket accepting.\n");
	int pid=fork();
	while(1){
	if(pid>0){
		//parent
		printf("\n\nParent - Type message: ");
	scanf("%s", buff2);

	sntb=send(ns,buff2,sizeof(buff2),0);
	if(sntb==-1)
	{
		printf("\nMessage Sending Failed");
		close(s);
		close(ns);
		exit(0);
	}
	if(strcmp(buff2,"BYE")==0)
		break;
	}
	else{
		//child
		recb=recv(ns,buff,sizeof(buff),0);
	if(recb==-1)
	{
		printf("\nMessage Recieving Failed");		
		close(s);
		close(ns);
		exit(0);
	}	
	if(strcmp(buff,"BYE")==0)
		break;
	printf("\nChild - Message Recieved: ");
	printf("%s\n", buff);

	}
}
	
	

	close(ns);
	close(s);
}