服务器端：server.c
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/time.h>
#include <sys/types.h>
#define MAXBUF 1024
int main(int argc, char **argv)
{
int sockfd, new_fd;
socklen_t len;
struct sockaddr_in my_addr, their_addr;
unsigned int myport, lisnum;
char buf[MAXBUF + 1];
fd_set rfds;
struct timeval tv;
int retval, maxfd = -1;
if (argv[2])
myport = atoi(argv[2]); /* 将命令行字符串转换为整数。用于端口 */
else
myport = 8888; /* 设置默认端口 */
if (argv[3])
lisnum = atoi(argv[3]); /* 监听队列大小 */
else
lisnum = 2;
if ((sockfd = socket(PF_INET, SOCK_STREAM, 0)) == -1) { /* 创建socket对象 */
perror("socket");
exit(EXIT_FAILURE);
}
bzero(&my_addr, sizeof(my_addr));
my_addr.sin_family = PF_INET; /* 地址协议 */
my_addr.sin_port = htons(myport); /* 地址端口 */
if (argv[1])
my_addr.sin_addr.s_addr = inet_addr(argv[1]);
else
my_addr.sin_addr.s_addr = INADDR_ANY; /* 否则默认本机随意地址 */
if (bind(sockfd, (struct sockaddr *) &my_addr, sizeof(struct sockaddr)) == -1) { /* 绑定地址信息 */
perror("bind");
exit(EXIT_FAILURE);
}
if (listen(sockfd, lisnum) == -1) {
/* 监听网络 ，最大队列数是lisnum*/
perror("listen");
exit(EXIT_FAILURE);
}
while (1)
{
printf ("\n----wait for new connect\n");
len = sizeof(struct sockaddr);
if ((new_fd =accept(sockfd, (struct sockaddr *) &their_addr,&len)) == -1) {
/* 堵塞等待连接。连接成功返回新的socket描写叙述符，their_addr存储client的sockaddr 地址信息
perror("accept");
exit(errno);
} else
printf("server: got connection from %s, port %d, socket %d\n",
inet_ntoa(their_addr.sin_addr),ntohs(their_addr.sin_port), new_fd);
while (1)
{
FD_ZERO(&rfds);
/* 清零rfds集合 */
FD_SET(0, &rfds);
/* 把标准输入加入rfds集合 */
FD_SET(new_fd, &rfds); /*
把new_fd加入rfds集合 */
maxfd = new_fd;
tv.tv_sec = 1;
tv.tv_usec = 0;
retval = select(maxfd + 1, &rfds, NULL, NULL, &tv); /*
maxfd + 1监听的最大值加一 */
if (retval == -1)
{
perror("select");
exit(EXIT_FAILURE);
} else if (retval == 0) {
continue;
}
else
{
if (FD_ISSET(0, &rfds)) /* 假设是标准输入可读 */
{
bzero(buf, MAXBUF + 1);
fgets(buf, MAXBUF, stdin);
if (!strncasecmp(buf, "quit", 4)) {
printf("i will quit!\n");
break;
}
len = send(new_fd, buf, strlen(buf) - 1, 0);
if (len > 0)
printf ("send successful,%d byte send!\n",len);
else {
printf("send failure!");
break;
}
}
if (FD_ISSET(new_fd, &rfds)) /* 假设是new_fd可读 */
{
bzero(buf, MAXBUF + 1);
len = recv(new_fd, buf, MAXBUF, 0);
if (len > 0)
printf ("recv success :‘%s‘,%dbyte recv\n", buf, len);
else
{
if (len < 0)
printf("recv failure\n");
else
{
printf("the ohter one end ,quit\n");
break;
}
}
}
}
}
close(new_fd);
printf("need othe connecdt (no->quit)");
fflush(stdout);
bzero(buf, MAXBUF + 1);
fgets(buf, MAXBUF, stdin);
if (!strncasecmp(buf, "no", 2))
{
printf("quit!\n");
break;
}
}
close(sockfd);
return 0;
}
客户端程序：client.c
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <sys/socket.h>
#include <resolv.h>
#include <stdlib.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <sys/time.h>
#include <sys/types.h>
#define MAXBUF 1024
int main(int argc, char **argv)
{
int sockfd, len;
struct sockaddr_in dest;
char buffer[MAXBUF + 1];
fd_set rfds;
struct timeval tv;
int retval, maxfd = -1;
if (argc != 3)
{
printf("argv format errno,pls:\n\t\t%s IP port\n",argv[0], argv[0]);
exit(EXIT_FAILURE);
}
if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
{
perror("Socket");
exit(EXIT_FAILURE);
}
bzero(&dest, sizeof(dest));
dest.sin_family = AF_INET;
dest.sin_port = htons(atoi(argv[2]));
if (inet_aton(argv[1], (struct in_addr *) &dest.sin_addr.s_addr) == 0)
{
perror(argv[1]);
exit(EXIT_FAILURE);
}
if (connect(sockfd, (struct sockaddr *) &dest, sizeof(dest)) != 0)
{
perror("Connect ");
exit(EXIT_FAILURE);
}
printf("\nget ready pls chat\n");
while (1)
{
FD_ZERO(&rfds);
FD_SET(0, &rfds);
FD_SET(sockfd, &rfds);
maxfd = sockfd;
tv.tv_sec = 1;
tv.tv_usec = 0;
retval = select(maxfd + 1, &rfds, NULL, NULL, &tv);
if (retval == -1)
{
printf("select %s", strerror(errno));
break;
}
else if (retval == 0)
continue;
else
{
if (FD_ISSET(sockfd, &rfds))
{
bzero(buffer, MAXBUF + 1);
len = recv(sockfd, buffer, MAXBUF, 0);
if (len > 0)
printf ("recv message:‘%s‘,%d byte recv\n",buffer, len);
else
{
if (len < 0)
printf ("message recv failure\n");
else
{
printf("the othe quit ,quit\n");
break;
}
}
}
if (FD_ISSET(0, &rfds))
{
bzero(buffer, MAXBUF + 1);
fgets(buffer, MAXBUF, stdin);
if (!strncasecmp(buffer, "quit", 4)) {
printf("i will quit\n");
break;
}
len = send(sockfd, buffer, strlen(buffer) - 1, 0);
if (len < 0) {
printf ("message send failure");
break;
} else
printf
("send success,%d byte send\n",len);
}
}
}
close(sockfd);
return 0;
}
測试方法例如以下：
gcc server.c -o server
gcc client.c -o client
./server 172.16.148.114 8888 /* 一个终端下。172.16.148.114是我虚拟机的IP地址*/
./client 172.16.148.114 8888 /*另外 一个终端下 */
select函数不会使用的參考这篇文章：http://blog.csdn.net/qq_21792169/article/details/50450360