#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>  /* for memset() */
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <pthread.h>   /* NOT IN STARTER */

int nclients = 0;
int clientfds[100];


int main(int argc, char **argv)
{
    int port = 1234;
    int listenfd, newfd;
    struct sockaddr_in r;
    socklen_t len;
    pthread_t t;
    extern void *deal_with_client(void *arg);

    if (argc == 2)
	port = atoi(argv[1]);

    if ((listenfd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
	perror("socket");
	return(1);
    }
    memset(&r, '\0', sizeof r);
    r.sin_family = AF_INET;
    r.sin_addr.s_addr = INADDR_ANY;
    r.sin_port = htons(port);
    if (bind(listenfd, (struct sockaddr *)&r, sizeof r)) {
	perror("bind");
	exit(1);
    }
    if (listen(listenfd, 5)) {
	perror("listen");
	exit(1);
    }

    while (1) {
	len = sizeof r;
	if ((newfd = accept(listenfd, (struct sockaddr *)&r, &len)) < 0) {
	    perror("accept");
	} else {
	    clientfds[nclients] = newfd;
	    pthread_create(&t, NULL, deal_with_client, &clientfds[nclients]);
	    nclients++;
	}
    }
}


void *deal_with_client(void *arg)
{
    int fd = *(int *)arg;
    int i, nbytes;
    char buf[1000];  /* should be MAXMESSAGE or something */

    static char greeting[] = "chatsvr blah blah\r\n";
    printf("new connection, fd %d\n", fd);
    write(fd, greeting, sizeof greeting - 1);

    while ((nbytes = read(fd, buf, sizeof buf)) > 0)
	for (i = 0; i < nclients; i++)
	    if (clientfds[i] >= 0)
		write(clientfds[i], buf, nbytes);

    printf("lost connection %d\n", fd);
    close(fd);
    *(int *)arg = -1;
    return(NULL);
}