Write client and server programs(using c)for interaction between server and client processes using Internet Domain sockets.

AIM :

Write a client and server programs(using c)for interaction between server and client processes using Internet Domain sockets.

Program:

Server program:

#include <stdio.h>
#include <sys/types.h> 
#include <sys/socket.h>
#include <netinet/in.h>
void error(char *msg)
{
    perror(msg);
    exit(1);
}
int main(int argc, char *argv[])
{
     int sockfd, newsockfd, portno, clilen;
     char buffer[256];
     struct sockaddr_in serv_addr, cli_addr; 
     int n; 
    if (argc < 2)
    { 
        fprintf(stderr,"ERROR, no port provided\n");
        exit(1);
     }
        sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd < 0)
        error("ERROR opening socket"); 
        bzero((char *) &serv_addr, sizeof(serv_addr));
        portno = atoi(argv[1]);
        serv_addr.sin_family = AF_INET; 
        serv_addr.sin_addr.s_addr = INADDR_ANY;
        serv_addr.sin_port = htons(portno); 
    if (bind(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0)
        error("ERROR on binding");
        listen(sockfd,5);  
        clilen = sizeof(cli_addr); 
        newsockfd = accept(sockfd, (struct sockaddr *) &cli_addr, &clilen);
     if (newsockfd < 0)  
        error("ERROR on accept"); 
        bzero(buffer,256);   
        n = read(newsockfd,buffer,255);
     if (n < 0) 
        error("ERROR reading from socket");
        printf("Here is the message: %s\n",buffer);   
        n = write(newsockfd,"I got your message",18);   
     if (n < 0) error("ERROR writing to socket");    
        return 0; 
}

Client Program:

#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h> 
void error(char *msg)
{    perror(msg);  
     exit(0);
}
int main(int argc, char *argv[])
{ 
   int sockfd, portno, n;
   struct sockaddr_in serv_addr;
   struct hostent *server;  
   char buffer[256]; 
   if (argc < 3)
   {       
       fprintf(stderr,"usage %s hostname port\n", argv[0]);
       exit(0);   
   } 
       portno = atoi(argv[2]);  
       sockfd = socket(AF_INET, SOCK_STREAM, 0);   
   if (sockfd < 0)  
       error("ERROR opening socket");
       server = gethostbyname(argv[1]);   
   if (server == NULL) 
   {       
       fprintf(stderr,"ERROR, no such host\n");
       exit(0);
   }   
       bzero((char *) &serv_addr, sizeof(serv_addr));
       serv_addr.sin_family = AF_INET;
       bcopy((char *)server->h_addr,(char *)&serv_addr.sin_addr.s_addr,server->h_length);
       serv_addr.sin_port = htons(portno);
   if (connect(sockfd,(struct sockaddr *)&serv_addr,sizeof(serv_addr)) < 0)
       error("ERROR connecting");
       printf("Please enter the message: ");
       bzero(buffer,256);
       fgets(buffer,255,stdin);
       n = write(sockfd,buffer,strlen(buffer));
   if (n < 0) 
       error("ERROR writing to socket");
       bzero(buffer,256);
       n = read(sockfd,buffer,255);
   if (n < 0) 
      error("ERROR reading from socket");
      printf("%s\n",buffer);
      return 0;
}

Output:

Student@ubuntu:~$gcc –o server2.out server2.c
Student@ubuntu:~$gcc –o client2.out client2.c
Please enter the message
Hello world
Hello world I got ur message
Student@ubuntu:~$ ./server2.out
Here is the message hello world