Socket programming with TCP | TCP Socket program in UNIX | Server - Client socket program using TCP

     Socket programming with TCP

TCP Socket Program - Server

#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: %s\t 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);

}

 

Compilation:

gcc server.c -o server 

./server

 

Output:

Socket successfully created..

Socket successfully binded..

Server listening..

server accept the client...

From client: hi

     To client : hello

From client: exit

     To client : exit

Server Exit...

 

TCP Socket Program – Client

#include <netdb.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <sys/socket.h>

#define MAX 80

#define PORT 8080

#define SA struct sockaddr

void func(int sockfd)

{

     char buff[MAX];

     int n;

     for (;;) {

                 bzero(buff, sizeof(buff));

                 printf("Enter the string : ");

                 n = 0;

                 while ((buff[n++] = getchar()) != '\n')

                             ;

                 write(sockfd, buff, sizeof(buff));

                 bzero(buff, sizeof(buff));

                 read(sockfd, buff, sizeof(buff));

                 printf("From Server : %s", buff);

                 if ((strncmp(buff, "exit", 4)) == 0) {

                             printf("Client Exit...\n");

                             break;

                 }

     }

}

 

int main()

{

     int sockfd, connfd;

     struct sockaddr_in servaddr, cli;

 

     // socket create and varification

     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 = inet_addr("127.0.0.1");

     servaddr.sin_port = htons(PORT);

 

     // connect the client socket to server socket

     if (connect(sockfd, (SA*)&servaddr, sizeof(servaddr)) != 0) {

                 printf("connection with the server failed...\n");

                 exit(0);

     }

     else

                 printf("connected to the server..\n");

 

     // function for chat

     func(sockfd);

 

     // close the socket

     close(sockfd);

}

 

Compilation:

gcc client.c -o client 

./client

 

Output:

Socket successfully created..

connected to the server..

Enter the string : hi

From Server : hello

Enter the string : exit

From Server : exit

Client Exit...