Notes

#include <stdio.h>
#include <netdb.h>
#include <netinet/in.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/types.h>
#define MAX 80
#define PORT 8080
#define SA struct sockaddr

// Function designed for chat between client and server.
void func(int connfd)
{
char buff[MAX];
int n;
// infinite loop for chat
for (;;) {
bzero(buff, MAX);

// read the message from client and copy it in buffer
read(connfd, buff, sizeof(buff));
// print buffer which contains the client contents
printf("From client: %st To client : ", buff);
bzero(buff, MAX);
n = 0;
// copy server message in the buffer
while ((buff[n++] = getchar()) != 'n')
;

// and send that buffer to client
write(connfd, buff, sizeof(buff));

// if msg contains "Exit" then server exit and chat ended.
if (strncmp("exit", buff, 4) == 0) {
printf("Server Exit...n");
break;
}
}
}

// Driver function
int main()
{
int sockfd, connfd, len;
struct sockaddr_in servaddr, cli;

// socket create and verification
sockfd = socket(AF_INET, SOCK_STREAM, 0);
if (sockfd == -1) {
printf("socket creation failed...n");
exit(0);
}
else
printf("Socket successfully created..n");
bzero(&servaddr, sizeof(servaddr));

// assign IP, PORT
servaddr.sin_family = AF_INET;
servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
servaddr.sin_port = htons(PORT);

// Binding newly created socket to given IP and verification
if ((bind(sockfd, (SA*)&servaddr, sizeof(servaddr))) != 0) {
printf("socket bind failed...n");
exit(0);
}
else
printf("Socket successfully binded..n");

// Now server is ready to listen and verification
if ((listen(sockfd, 5)) != 0) {
printf("Listen failed...n");
exit(0);
}
else
printf("Server listening..n");
len = sizeof(cli);

// Accept the data packet from client and verification
connfd = accept(sockfd, (SA*)&cli, &len);
if (connfd < 0) {
printf("server accept failed...n");
exit(0);
}
else
printf("server accept the client...n");

// Function for chatting between client and server
func(connfd);

// After chatting close the socket
close(sockfd);
}