server.c

/*
First run server.c by gcc server.c -o server
then run server by ./server
After that start client by  gcc client.c -o client
then run client by ./client
*/
#include<stdio.h>
#include<string.h>
#include<sys/socket.h>
#include<stdlib.h>
#include<netdb.h>
#include<unistd.h>

int main()
{
    int serversocket,clientsocket,port; //clientsocket is the socket descriptor , port is the port number
    struct sockaddr_in serveraddr,clientaddr; //creating a structure of type sockaddr_in for server
    socklen_t len; //creating a variable to store the length of the server address 
    char message[50]; //
    struct serveraddr; //creating a structure of type sockaddr_in for server


    serversocket=socket(AF_INET,SOCK_STREAM,0); //creating a socket
    bzero((char*)&serveraddr,sizeof(serveraddr));//initializing the server address to zero
    serveraddr.sin_family=AF_INET;//setting the family of the server address to AF_INET

    printf("Enter the port number ");
    scanf("%d",&port);

    serveraddr.sin_port=htons(port); //setting the port number of the server address to port
    serveraddr.sin_addr.s_addr=INADDR_ANY; //setting the IP address of the server address to INADDR_ANY
    bind(serversocket,(struct sockaddr*)&serveraddr,sizeof(serveraddr)); //binding the server address to the socket
    bzero((char*)&clientaddr,sizeof(clientaddr)); //initializing the client address to zero
    len=sizeof(clientaddr); //storing the length of the client address in len
    listen(serversocket,5); //listening to the socket, 5 is the number of clients that can connect to the server

    printf("\nWaiting for client connection\n"); 
    printf("\nhai:");
    clientsocket=accept(serversocket,(struct sockaddr*)&clientaddr,&len);//accepting the client connection

    printf("\nClient connectivity received.\n");
    printf("\nReading message from the client.\n");
    read(clientsocket,message,sizeof(message));//reading the message from the client

    printf("\nThe client has sent.%s",message);
    printf("\nSending message to the client.\n");
    write(clientsocket,"YOUR MESSAGE RECEIVED.",sizeof("YOUR MESSAGE RECEIVED."));//sending the message to the client
    
    close(clientsocket);//closing the client socket
    close(serversocket);//closing the server socket


}

/*
OUTPUT
s6d2@user-HP-280-G3-MT:~/Networking-Lab-S6/Socket-Programming/TCP$ gcc server.c -o server
s6d2@user-HP-280-G3-MT:~/Networking-Lab-S6/Socket-Programming/TCP$ ./server
Enter the port number 6000

Waiting for client connection

hai:
Client connectivity received.

Reading message from the client.

The client has sent.HI,IAM CLIENT...
Sending message to the client.
s6d2@user-HP-280-G3-MT:~/Networking-Lab-S6/Socket-Programming/TCP$ ^C
*/