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Posted on 2009-12-01 15:37 大源 阅读(1239) 评论(0) 编辑 收藏 引用 所属分类: C/C++
Linux下写了个小的socket程序，分为客户端和服务器端,服务端开一个端口(2000),做为一个
daemon,等待客户的连接请求.一旦有客户连接,服务器端打印出客户端的IP地址和端口,并且向服务
器端发送欢迎信息和时间.下面是服务端的代码(tcpserver.c).由于这只是个简单的程序，所以只用
了单线程实现!
1 /**
2 * Tcp Server program, It is a simple example only.
3 * zhengsh 200520602061 2
4 * when client connect to server, send a welcome message and timestamp in server.
5 */
6
7#include <stdio.h>
8#include <sys/socket.h>
9#include <unistd.h>
10#include <sys/types.h>
11#include <netinet/in.h>
12#include <stdlib.h>
13#include <time.h>
14
15#define SERVER_PORT 20000 // define the defualt connect port id
16#define LENGTH_OF_LISTEN_QUEUE 10 //length of listen queue in server
17#define BUFFER_SIZE 255
18#define WELCOME_MESSAGE "welcome to connect the server. "
19
20
21int main(int argc, char **argv)
22{
23 int servfd,clifd;
24 struct sockaddr_in servaddr,cliaddr;
25
26 if ((servfd = socket(AF_INET,SOCK_STREAM,0)) < 0)
27 {
28 printf("create socket error!\n");
29 exit(1);
30 }
31 bzero(&servaddr,sizeof(servaddr));
32 servaddr.sin_family = AF_INET;
33 servaddr.sin_port = htons(SERVER_PORT);
34 servaddr.sin_addr.s_addr = htons(INADDR_ANY);
35
36 if (bind(servfd,(struct sockaddr*)&servaddr,sizeof(servaddr))<0)
37 {
38 printf("bind to port %d failure!\n",SERVER_PORT);
39 exit(1);
40 }
41
42 if (listen(servfd,LENGTH_OF_LISTEN_QUEUE) < 0)
43 {
44 printf("call listen failure!\n");
45 exit(1);
46 }
47
48 while (1)
49 {//server loop will nerver exit unless any body kill the process
50 char buf[BUFFER_SIZE];
51 long timestamp;
52 socklen_t length = sizeof(cliaddr);
53 clifd = accept(servfd,(struct sockaddr*)&cliaddr,&length);
54 if (clifd < 0)
55 {
56 printf("error comes when call accept!\n");
57 break;
58 }
59 strcpy(buf,WELCOME_MESSAGE);
60 //inet_ntop(INET_ADDRSTRLEN,cliaddr.sin_addr,buf,BUFFER_SIZE);
61
62 printf("from client,IP:%s,Port:%d\n",inet_ntoa(cliaddr.sin_addr),ntohs(cliaddr.sin_port));
63 timestamp = time(NULL);
64 strcat(buf,"timestamp in server:");
65 strcat(buf,ctime(×tamp));
66 send(clifd,buf,BUFFER_SIZE,0);
67 close(clifd);
68
69 }//exit
70 close(servfd);
71 return 0;
72}
客户每次用一个随机的端口连接服务器,并接收来自服务器的欢迎信息
,然后打印出来(tcpclient).运行的时候接受一个参数,也就是服务器的ip地址.
1/* Tcp client program, It is a simple example only.
2 * zhengsh 200520602061 2
3 * connect to server, and echo a message from server.
4 */
5
6
7#include <stdio.h>
8#include <sys/socket.h>
9#include <unistd.h>
10#include <sys/types.h>
11#include <netinet/in.h>
12#include <stdlib.h>
13
14#define SERVER_PORT 20000 // define the defualt connect port id
15#define CLIENT_PORT ((20001+rand())%65536) // define the defualt client port as a random port
16
17#define BUFFER_SIZE 255
18#define REUQEST_MESSAGE "welcome to connect the server.\n"
19
20void usage(char *name)
21{
22 printf("usage: %s IpAddr\n",name);
23}
24
25int main(int argc, char **argv)
26{
27 int servfd,clifd,length = 0;
28 struct sockaddr_in servaddr,cliaddr;
29 socklen_t socklen = sizeof(servaddr);
30 char buf[BUFFER_SIZE];
31
32 if (argc < 2)
33 {
34 usage(argv[0]);
35 exit(1);
36 }
37
38 if ((clifd = socket(AF_INET,SOCK_STREAM,0)) < 0)
39 {
40 printf("create socket error!\n");
41 exit(1);
42 }
43 srand(time(NULL));//initialize random generator
44 bzero(&cliaddr,sizeof(cliaddr));
45 cliaddr.sin_family = AF_INET;
46 cliaddr.sin_port = htons(CLIENT_PORT);
47 cliaddr.sin_addr.s_addr = htons(INADDR_ANY);
48
49 bzero(&servaddr,sizeof(servaddr));
50 servaddr.sin_family = AF_INET;
51 inet_aton(argv[1],&servaddr.sin_addr);
52 servaddr.sin_port = htons(SERVER_PORT);
53 //servaddr.sin_addr.s_addr = htons(INADDR_ANY);
54
55 if (bind(clifd,(struct sockaddr*)&cliaddr,sizeof(cliaddr))<0)
56 {
57 printf("bind to port %d failure!\n",CLIENT_PORT);
58 exit(1);
59 }
60
61 if (connect(clifd,(struct sockaddr*)&servaddr, socklen) < 0)
62 {
63 printf("can't connect to %s!\n",argv[1]);
64 exit(1);
65 }
66
67 length = recv(clifd,buf,BUFFER_SIZE,0);
68 if (length < 0)
69 {
70 printf("error comes when recieve data from server %s!",argv[1]);
71 exit(1);
72 }
73 printf("from server %s :\n\t%s ",argv[1],buf);
74
75 close(clifd);
76 return 0;
77}
程序在Fedora core 4下通过编译,有几个warining.但是不影响.
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