Notes

#include <unistd.h>
#include <stdio.h>
#include <sys/socket.h>
#include<sys/types.h>
#include<arpa/inet.h>
#include <stdlib.h>
#include <netinet/ip.h>
#include<sys/times.h>
#include <string.h>
#define PORT 8080
int main(int argc, char const *argv[])
{
int serverfd, new_socket, valread;
struct sockaddr_in server,client;;
int addrlen = sizeof(server);
int opt=1;
// Creating socket file descriptor
if ((serverfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1)
{
perror("socket failed");
exit(EXIT_FAILURE);
}

// Forcefully attaching socket to the port 8080
if (setsockopt(serverfd, SOL_SOCKET, SO_REUSEADDR,&opt,sizeof(opt)))
{
perror("setsockopt");
exit(EXIT_FAILURE);
}
server.sin_family = AF_INET;
server.sin_addr.s_addr = INADDR_ANY;
server.sin_port = htons( PORT );

// Forcefully attaching socket to the port 8080
if (bind(serverfd, (struct sockaddr *)&server,
sizeof(server))<0)
{
perror("bind failed");
exit(EXIT_FAILURE);
}
if (listen(serverfd, 10) < 0)
{
perror("listen");
exit(EXIT_FAILURE);
}

fd_set readfd,copyfd;
FD_ZERO(&readfd);
FD_SET(serverfd,&readfd);
struct timeval tv;
int maxfd=serverfd+1;
int clientfd[10];
int i=0,j,size=sizeof(server);
char rcv[20],snd[20];
int ret;
char ipaddr[50];
while(1)
{
copyfd=readfd;
tv.tv_sec=5;
tv.tv_usec=5000000;
ret=select(maxfd,&copyfd,NULL,NULL,&tv);
if(ret<0)
printf("Select errorn");
if(ret==0)
printf("Timeoutn");
else
{
if(FD_ISSET(serverfd,&copyfd))
{
clientfd[i]=accept(serverfd,(struct sockaddr *)&client,&size);
if(clientfd[i]<0)
{
perror("Accept error");
exit(1);
}
printf("Connection accepted from %s clientn",inet_ntoa(client.sin_addr));
if(maxfd<=clientfd[i])
{
maxfd=clientfd[i]+1;
FD_SET(clientfd[i],&readfd);
i++;
}
}
for(j=0;j<i;j++)
{
if(FD_ISSET(clientfd[j],&copyfd))
{
int r=recv(clientfd[j],rcv,sizeof(rcv),0);
rcv[r]='';
strcpy(ipaddr,inet_ntoa(client.sin_addr));
if(r==0)
{
printf("%s is closed the connectionn",ipaddr);
close(clientfd[j]);
FD_CLR(clientfd[j],&readfd);
break;
}
printf("Message from client is %sn",rcv);
}
}
}
}
return 0;
}