Question

Client AND server using names pipes (mkfifo) in C/C++

Write and client program that will talk to a server program in two separate terminals.

Write the server program that can handle multiple clients (so threads will be needed) and with fork() and exec()

Answer 1

/Below code will as you wanted...

//server.c

/*

** C socket server example, handles multiple clients using threads

** Compile

** gcc server.c -lpthread -o server

*/

#include <stdio.h>

#include <string.h> // strlen

#include <stdlib.h> // strlen

#include <sys/socket.h>

#include <arpa/inet.h> //inet_addr

#include <unistd.h> // write

#include <pthread.h> // for threading, link with lpthread

// the thread function

void *connection_handler(void *);

int main(int argc, char *argv[]) {

   int socket_desc, client_sock, c;

   struct sockaddr_in server, client;

   // Create socket

   socket_desc = socket(AF_INET, SOCK_STREAM, 0);

   if(socket_desc == -1) {

       printf("Could not create socket");

   }

   puts("Socket created");

   // Prepare the sockaddr_in structure

   server.sin_family = AF_INET;

   server.sin_addr.s_addr = INADDR_ANY;

   server.sin_port = htons(8888);

   // Bind

   if(bind(socket_desc,(struct sockaddr *)&server, sizeof(server)) < 0) {

       // print the error message

       perror("bind failed. Error");

       return 1;

   }

   puts("bind done");

   // Listen

   listen(socket_desc, 3);

   // Accept and incoming connection

   puts("Waiting for incoming connections...");

   c = sizeof(struct sockaddr_in);

   // Accept and incoming connection

   puts("Waiting for incoming connections...");

   c = sizeof(struct sockaddr_in);

   pthread_t thread_id;

   while((client_sock = accept(socket_desc, (struct sockaddr *)&client, (socklen_t*)&c))) {

       puts("Connection accepted");

       if(pthread_create( &thread_id, NULL, connection_handler, (void*) &client_sock) < 0) {

           perror("could not create thread");

           return 1;

       }

       // Now join the thread, so that we dont terminate before the thread

       // pthread_join( thread_id, NULL);

       puts("Handler assigned");

   }

   if (client_sock < 0) {

       perror("accept failed");

       return 1;

   }

   return 0;

}

//

// This will handle connection for each client

//

void *connection_handler(void *socket_desc) {

   // Get the socket descriptor

   int sock = *(int*)socket_desc;

   int read_size;

   char *message, client_message[2000];

   // Send some messages to the client

   message = "Greetings! I am your connection handler\n";

   write(sock, message, strlen(message));

   message = "Now type something and i shall repeat what you type \n";

   write(sock, message, strlen(message));

   // Receive a message from client

   while( (read_size = recv(sock, client_message, 2000, 0)) > 0 ) {

       // end of string marker

       client_message[read_size] = '\0';

       // Send the message back to client

       write(sock, client_message, strlen(client_message));

       // clear the message buffer

       memset(client_message, 0, 2000);

   }

   if(read_size == 0) {

       puts("Client disconnected");

       fflush(stdout);

   }

   else if(read_size == -1) {

       perror("recv failed");

   }

   return 0;

}

//client.c

/* CLIENT CODE */

#include <stdio.h>

#include <sys/socket.h>

#include <netinet/in.h>

#include <string.h>

int main()

{

int clientSocket;

char buffer[1024];

struct sockaddr_in serverAddr;

socklen_t addr_size;

/*---- Create the socket. The three arguments are: ----*/

/* 1) Internet domain 2) Stream socket 3) Default protocol (TCP in this case) */

clientSocket = socket(PF_INET, SOCK_STREAM, 0);

  

/*---- Configure settings of the server address struct ----*/

/* Address family = Internet */

serverAddr.sin_family = AF_INET;

/* Set port number, using htons function to use proper byte order */

serverAddr.sin_port = htons(8888);

/* Set IP address to localhost */

serverAddr.sin_addr.s_addr = inet_addr("127.0.0.1");

/* Set all bits of the padding field to 0 */

memset(serverAddr.sin_zero, '\0', sizeof serverAddr.sin_zero);

/*---- Connect the socket to the server using the address struct ----*/

addr_size = sizeof serverAddr;

connect(clientSocket, (struct sockaddr *) &serverAddr, addr_size);

/*---- Read the message from the server into the buffer ----*/

recv(clientSocket, buffer, 1024, 0);

/*---- Print the received message ----*/

printf("Data received: %s",buffer);   

return 0;

}

output: