EX3:Write a program to Echo from server to client using TCP socket

EX3:Write a program to Echo from server to client using TCP socket

Algorithm:

Server:

1.      Create a socket with the socket() system call.

2.     Bind the socket to an address using the bind() system call. For a server socket on the Internet, an address consists of a port number on the host machine.

3.     Listen for connections with the listen() system call.

4.   Accept a connection with the accept() system call. This call typically blocks until a client connects with the server.

5.      Send and receive data using the read() and write() system calls.

6.      Terminate the connections using close() system call.

Client:

1.      Create a socket with the socket() system call.

2.   Connect the socket to the address of the server using the connect() system call.

3.      Send and receive data using the read() and write() system calls.

4.      Terminate the connections using close() system call.

Server Program:

#include<stdio.h>
#include<netinet/in.h>
#include<sys/types.h>
#include<sys/socket.h>
#include<netdb.h>
#include<string.h>
#include<stdlib.h>
#include<unistd.h>
#include<arpa/inet.h>
#include<errno.h>
#include<time.h>
#define MAX 80
#define PORT 43454
#define SA struct sockaddr
void func(int sockfd)
{
        char buff[MAX];
        for(;;)
        {
                bzero(buff,MAX);
                read(sockfd,buff,sizeof(buff));
                printf("from client: %s\n",buff);
                write(sockfd,buff,sizeof(buff));
                if(strncmp("exit",buff,4)==0)
                {
                        printf("server exit...\n");
                        break;
                }
        }
}
int main()
{
        int sockfd,connfd,len;
        struct sockaddr_in servaddr,cli;
        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));
        servaddr.sin_family=AF_INET;
        servaddr.sin_addr.s_addr=htonl(INADDR_ANY);
        servaddr.sin_port=htons(PORT);
        if((bind(sockfd,(SA*)&servaddr,sizeof(servaddr)))!=0)
        {
                printf("socket bind failed...\n");
                exit(0);
        }
        else
                printf("socket successfully binded...\n");
        if((listen(sockfd,5))!=0)
        {
                printf("listen failed...\n");
                exit(0);
        }
        else
                printf("server listening...\n");
        len=sizeof(cli);
        connfd=accept(sockfd,(SA*)&cli,&len);
        if(connfd<0)
        {
                printf("server accept failed...\n");
                exit(0);
        }
        else
                printf("server accept the client...\n");
        func(connfd);
        close(sockfd);
}

Client Program:

#include<stdio.h>
#include<netinet/in.h>
#include<sys/types.h>
#include<sys/socket.h>
#include<netdb.h>
#include<string.h>
#include<stdlib.h>
#include<unistd.h>
#include<arpa/inet.h>
#include<errno.h>
#include<time.h>
#define MAX 80
#define PORT 43454
#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;
        sockfd = socket(AF_INET,SOCK_STREAM,0);
        if(sockfd==-1)
        {
                printf("socket creation failed...\n");
                exit(0);
        }
        else
        printf("socket successfully created" );
        bzero(&servaddr,sizeof(servaddr));
        servaddr.sin_family=AF_INET;
        servaddr.sin_addr.s_addr=inet_addr("127.0.0.1");
        servaddr.sin_port=htons(PORT);
        if(connect(sockfd,(SA*)&servaddr,sizeof(servaddr))!=0)
        {
                printf("connection with the server failed...\n");
                exit(0);
        }
        else
                printf("connected to the server... \n");
        func(sockfd);
        close(sockfd);
}

OUTPUT:

SERVER:

[tec@tecnetserver anand]$ cc serecho.c

[tec@tecnetserver anand]$ cc serecho.c -o ser

[tec@tecnetserver anand]$ ./ser

Socket successfully created..

socket successfully binded..

Server listening..

server accept the client...

From Client:Hello

From Client:Hai

From Client:exit

server exit....

[tec@tecnetserver anand]$

CLIENT:

[tec@tecnetserver anand]$ cc cliecho.c

[tec@tecnetserver anand]$ cc cliecho.c -o cli

[tec@tecnetserver anand]$ ./cli

socket successfully createdconnected to server..

 Enter the String:Hello

From Server:Hello

 Enter the String:Hai

From Server:Hai

 Enter the String:exit

From Server:exit

client exit.

[tec@tecnetserver anand]$