multithread server/client implementation in C

You can create multiple clients using thread. Create a separate thread for each client and then from thread handler connect to the server. I am not sure if it is a good way or not.

Code:

#include <stdio.h>#include <string.h>#include <sys/types.h>#include <sys/socket.h>#include <netinet/in.h>#include <arpa/inet.h>#include <stdlib.h>#include <unistd.h>#define MAX_SIZE 50#define NUM_CLIENT 5void *connection_handler(void *socket_desc);int main(){    int socket_desc , new_socket , c , *new_sock, i;    pthread_t sniffer_thread;    for (i=1; i<=NUM_CLIENT; i++) {        if( pthread_create( &sniffer_thread , NULL ,  connection_handler , (void*) i) < 0)        {            perror("could not create thread");            return 1;        }        sleep(3);    }    pthread_exit(NULL);    return 0;}void *connection_handler(void *threadid){    int threadnum = (int)threadid;    int sock_desc;    struct sockaddr_in serv_addr;    char sbuff[MAX_SIZE],rbuff[MAX_SIZE];    if((sock_desc = socket(AF_INET, SOCK_STREAM, 0)) < 0)        printf("Failed creating socket\n");    bzero((char *) &serv_addr, sizeof (serv_addr));    serv_addr.sin_family = AF_INET;    serv_addr.sin_addr.s_addr = inet_addr("127.0.0.1");    serv_addr.sin_port = htons(8888);    if (connect(sock_desc, (struct sockaddr *) &serv_addr, sizeof (serv_addr)) < 0) {        printf("Failed to connect to server\n");    }    printf("Connected successfully client:%d\n", threadnum);    while(1)    {        printf("For thread : %d\n", threadnum);        fgets(sbuff, MAX_SIZE , stdin);        send(sock_desc,sbuff,strlen(sbuff),0);        if(recv(sock_desc,rbuff,MAX_SIZE,0)==0)            printf("Error");        else           fputs(rbuff,stdout);        bzero(rbuff,MAX_SIZE);        sleep(2);    }    close(sock_desc);    return 0;}

For understanding purpose, i used sleep.

REF:

http://www.amazon.com/UNIX-Network-Programming-Richard-Stevens/dp/0139498761

http://beej.us/guide/bgnet/

https://computing.llnl.gov/tutorials/pthreads/

Firstly, if you fork(), you will be creating additional processes, not additional threads. To create additional threads, you want to use pthread_create.

Secondly, as you are a student, the canonical answer here is 'read Stephens'. Not only is this an invaluable tool even for those of us experienced in writing socket I/O routines, but also it contains examples of non-threaded non-forking async I/O, and various ways to add threads and forking to them. I believe the one you want is: http://www.amazon.com/Programming-Environment-Addison-Wesley-Professional-Computing/dp/0321637739 (chapter 14 if memory serves). This should be in your college library.