#include <stdio.h>

#include <sys/socket.h>

#include <netinet/in.h>

#include <string.h>

#define BACKLOG 5

#define BUFF_SIZE 6

#define PORT 9999

int fd[BACKLOG];

int con_num;

void ha_ha(void)

{

sleep(1);

}

int main(int argc, char** argv)

{

int sock_fd, new_fd;

struct sockaddr_in server_addr;

struct sockaddr_in client_addr;

socklen_t sin_size;

fd_set fdsr;

struct timeval tv;

char buf[BUFF_SIZE+1];

int ret = 0;

int i = 0;

sock_fd = socket(AF_INET, SOCK_STREAM, 0);

server_addr.sin_family = AF_INET;

server_addr.sin_port = htons(PORT);

server_addr.sin_addr.s_addr = INADDR_ANY;

memset(server_addr.sin_zero, 0, sizeof(server_addr.sin_zero));

bind(sock_fd, (struct sockaddr*)&server_addr, sizeof(server_addr));

listen(sock_fd, BACKLOG);

printf("listening...\n");

while(1)

{

FD_ZERO(&fdsr);

FD_SET(sock_fd, &fdsr);

tv.tv_sec = 1;

tv.tv_usec = 0;

for(i = 0; i < BACKLOG; i++)

{

if(fd[i] != 0)

{

FD_SET(fd[i], &fdsr);

}

}

select(sock_fd+BACKLOG, &fdsr, NULL, NULL, &tv);

if(FD_ISSET(sock_fd, &fdsr))

{

new_fd = accept(sock_fd, (struct sockaddr*)&client_addr, &sin_size);

if(con_num < BACKLOG)

{

fd[con_num++] = new_fd;

}

}

for(i = 0; i < con_num; i++)

{

if(FD_ISSET(fd[i], &fdsr))

{

ret = recv(fd[i], buf, BUFF_SIZE*sizeof(char), 0);

memset(&buf[ret], '\0', 1);

printf("%s\n", buf);

ha_ha();

send(fd[i], buf, BUFF_SIZE, 0);

}

}

}

return 0;

}