服务器端：
1: /*
2: * =====================================================================================
3: *
4: * Filename: server.c
5: *
6: * Description: tcp
7: *
8: * Version: 1.0
9: * Created: 03/11/2013 02:34:43 PM
10: * Revision: none
11: * Compiler: gcc
12: *
13: * Author: YOUR NAME (),
14: * Company:
15: *
16: * =====================================================================================
17: */
18:
19: #include
20: #include
21: #include
22: #include
23: #include
24: #include
25: #include
26: #include
27:
28: typedef struct sockaddr SA; //
29: #define N 128
30:
31: int main(int argc, char *argv[])
32: { 33: int listenfd, confd; //定义listend用于存放监听套接字的描述符，confd用于存放accept返回的已建立连接套接字的描述符。
34: struct sockaddr_in my_addr, peer_addr;//my_addr用于存放监听套接字要绑定的信息，peer_addr存放客户端套接字的信息
35: socklen_t peer_len = sizeof(my_addr); //peer_len最好定义时初始化，且必须初始化！
36: char buffer[N]; //
37:
38: if(argc < 3) //参数检查
39: { 40: printf("input error! %s \n",argv[0]); 41: exit(-1);
42: }
43:
44: if((listenfd = socket(PF_INET, SOCK_STREAM, 0)) < 0) //创建套接字，用于TCP连接
45: { 46: perror("socket error!"); 47: exit(-1);
48: }
49:
50: bzero(&my_addr, sizeof(my_addr)); //先将my_addr清空
51:
52: //初始化监听套接字的绑定信息
53: my_addr.sin_family = PF_INET; //网络协议
54:
55: /*
56: ./client 192.168.1.173 8888
57: argv[2]中是字符串“8888”的首地址，atoi将字符串“8888”，转化成数字8888，
58: 因为端口号是需要发送的，所以需要转换成网络字节序，通过htons实现
59: */
60: my_addr.sin_port = htons(atoi(argv[2]));
61:
62: my_addr.sin_addr.s_addr = inet_addr(argv[1]);//将字符串"192.168.1.173"转成32位的无符号整型
63:
64: if(bind(listenfd, (SA *)&my_addr, sizeof(my_addr)) < 0) //将监听套接字进行绑定
65: { 66: perror("error bind"); 67: exit(-1);
68: }
69:
70: if(listen(listenfd, 5) < 0) //将监听套接字设置为监听模式，等待请求队列长度为5
71: { 72:
73: perror("listen error!"); 74: exit(-1);
75: }
76:
77: signal(SIGCHLD, SIG_IGN); //防止产生僵尸进程，告诉OS，当子进程结束时，将子进程的task_struct也一并回收。
78:
79: while(1)
80: { 81: /*
82: 当没有客户端请求时，服务器在此阻塞。直到有客户端请求，然后返回一个新的套接字描述符confd，与
83: listenfd是相同类型的，但是confd可以用于与客户端收发数据，而listenfd不行，它只能监听。
84: 注意：accept返回的是一个新的已经与客户端建立连接的套接字confd，他有两个缓冲区，输入和输出，
85: 只有他才可以与客户端进行通信。他的类型与监听套接字一样。
86: */
87: if((confd = accept(listenfd, (SA *)&peer_addr, &peer_len)) < 0)
88: { 89: perror("accpt error!"); 90: exit(-1);
91: }
92:
93: printf("client : [%s:%d] on line!\n",inet_ntoa(peer_addr.sin_addr), ntohs(peer_addr.sin_port)); 94:
95: if(fork() == 0)
96: { 97: while(recv(confd, buffer, N,0) > 0) //将套接字confd的接收缓冲区的数据拷贝到buffer，当客户端关闭连接时，返回0。
98: { 99: printf("client : [%s:%d] > %s",inet_ntoa(peer_addr.sin_addr), ntohs(peer_addr.sin_port),buffer); 100: if(send(confd, buffer, N, 0) == -1) //将buffer中的数据拷贝到confd的发送缓冲区
101: { 102: perror("fail to send"); 103: exit(-1);
104: }
105: }
106:
107: printf("client : [%s:%d] offline!\n",inet_ntoa(peer_addr.sin_addr), ntohs(peer_addr.sin_port)); 108: close(confd);
109: exit(0);
110: }
111: close(confd);
112: }
113:
114: return 0;
115: }
客户端：
1: /*
2: * =====================================================================================
3: *
4: * Filename: server.c
5: *
6: * Description: tcp
7: *
8: * Version: 1.0
9: * Created: 03/11/2013 02:34:43 PM
10: * Revision: none
11: * Compiler: gcc
12: *
13: * Author: YOUR NAME (),
14: * Company:
15: *
16: * =====================================================================================
17: */
18:
19: #include
20: #include
21: #include
22: #include
23: #include
24: #include
25: #include
26: #include
27:
28:
29: #define N 128
30:
31: typedef struct sockaddr SA;
32:
33: int main(int argc, char *argv[])
34: { 35: int sockfd; //客户端套接字，客户端只需一个，且不需要绑定
36: struct sockaddr_in server_addr; //服务器的ip端口信息
37: char buffer[N];
38:
39: if(argc < 3)
40: { 41: printf("usage! %s \n",argv[0]); 42: exit(-1);
43: }
44:
45: if((sockfd = socket(PF_INET, SOCK_STREAM, 0)) < 0) //创建客户端套接字
46: { 47: perror("socket error!"); 48: exit(-1);
49: }
50:
51: bzero(&server_addr, sizeof(server_addr));
52:
53: /*
54: 初始化要连接的服务器信息
55: */
56: server_addr.sin_family = PF_INET;
57: server_addr.sin_port = htons(atoi(argv[2]));
58: server_addr.sin_addr.s_addr = inet_addr(argv[1]);
59:
60: if(connect(sockfd, (SA *)&server_addr, sizeof(server_addr)) < 0) //连接服务器
61: { 62: perror("fail to connect"); 63: exit(-1);
64: }
65:
66: printf("> "); 67: while(fgets(buffer, N, stdin) != 0)
68: { 69: //buffer[strlen(buffer) - 1] = '\0';
70: if(send(sockfd, buffer, N, 0) == -1)
71: { 72: perror("fail to send"); 73: exit(-1);
74: }
75: if(strncmp(buffer, "quit", 4) == 0)
76: { 77: break;
78: }
79: bzero(buffer, N);
80:
81: if(recv(sockfd, buffer, N, 0) == -1)
82: { 83: perror("fail to recv"); 84: exit(-1);
85: }
86: printf("-------->%s> ",buffer); 87: }
88: close(sockfd);
89:
90: return 0;
91: }