multi_client_server.c

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <string.h>
#define PORT 8000
#define MAXSZ 100
int main()
{
    int sockfd;
    int newsockfd;
    struct sockaddr_in servaddr;
    struct sockaddr_in clientaddr;
    int n;
    char msg[MAXSZ];
    int cli_len;
    int pid;
    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    memset(&servaddr, 0, sizeof(servaddr));
    servaddr.sin_family = AF_INET;
    servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
    servaddr.sin_port = htons(PORT);
    bind(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr));
    listen(sockfd, 5);

    while (1)
    {
        printf("\nServer waiting for new client connection:\n");
        cli_len = sizeof(clientaddr);
        newsockfd = accept(sockfd, (struct sockaddr *)&clientaddr, &cli_len);
        printf("connected to client:%s\n", inet_ntoa(clientaddr.sin_addr));
        pid = fork();
        if (pid == 0)
        {
            while (1)
            {
                n = recv(newsockfd, msg, MAXSZ, 0);
                if (n == 0)
                {
                    close(newsockfd);
                    break;
                }
                msg[n] = 0;
                send(newsockfd, msg, n, 0);
                printf("Receive and set:%s\n", msg);
            }
            exit(0);
        }
        else
        {
            close(newsockfd);
        }
    }
    return 0;
}