Linux网络编程一步一步学-UDP组播
组播客户端代码如下：
1.#include <sys/types.h> 2.#include <sys/socket.h> 3.#include <arpa/inet.h> 4.#include <stdio.h> 5.#include <stdlib.h> 6.#include <string.h> 7.8.#define BUFLEN 255 9./*********************************************************************
10.*filename: mcastclient.c
11.*purpose: 演示组播编程的基本步骤，其实这就是一个基本的UDP客户端程序
12.*tidied by: zhoulifa([email protected]) 周立发(http://zhoulifa.bokee.com)
13.Linux爱好者 Linux知识传播者 SOHO族 开发者 最擅长C语言
14.*date time:2007-01-25 13:10:00
15.*Note: 任何人可以任意复制代码并运用这些文档，当然包括你的商业用途
16.* 但请遵循GPL
17.*Thanks to: Google.com
18.*Hope:希望越来越多的人贡献自己的力量，为科学技术发展出力
19.* 科技站在巨人的肩膀上进步更快！感谢有开源前辈的贡献！
20.*********************************************************************/21.int main(int argc, char **argv)
22.{
23.struct sockaddr_in peeraddr, myaddr;
24.25.int sockfd;
26.char recmsg[BUFLEN + 1];
27.unsigned int socklen;
28.29./* 创建 socket 用于UDP通讯 */30.sockfd = socket(AF_INET, SOCK_DGRAM, 0);
31.if (sockfd < 0) {
32.printf("socket creating error/n");
33.exit(1);
34.}
35.socklen = sizeof(struct sockaddr_in);
36.37./* 设置对方的端口和IP信息 */38.memset(&peeraddr, 0, socklen);
39.peeraddr.sin_family = AF_INET;
40.if (argv[2])
41.peeraddr.sin_port = htons(atoi(argv[2]));
42.else43.peeraddr.sin_port = htons(7838);
44.if (argv[1]) {
45./* 注意这里设置的对方地址是指组播地址，而不是对方的实际IP地址 */46.if (inet_pton(AF_INET, argv[1], &peeraddr.sin_addr) <= 0) {
47.printf("wrong group address!/n");
48.exit(0);
49.}
50.} else {
51.printf("no group address!/n");
52.exit(0);
53.}
54.55./* 设置自己的端口和IP信息 */56.memset(&myaddr, 0, socklen);
57.myaddr.sin_family = AF_INET;
58.if (argv[4])
59.myaddr.sin_port = htons(atoi(argv[4]));
60.else61.myaddr.sin_port = htons(23456);
62.63.if (argv[3]) {
64.if (inet_pton(AF_INET, argv[3], &myaddr.sin_addr) <= 0) {
65.printf("self ip address error!/n");
66.exit(0);
67.}
68.} else69.myaddr.sin_addr.s_addr = INADDR_ANY;
70.71./* 绑定自己的端口和IP信息到socket上 */72.if (bind
73.(sockfd, (struct sockaddr *) &myaddr,
74.sizeof(struct sockaddr_in)) == -1) {
75.printf("Bind error/n");
76.exit(0);
77.}
78.79./* 循环接受用户输入的消息发送组播消息 */80.for (;;) {
81./* 接受用户输入 */82.bzero(recmsg, BUFLEN + 1);
83.if (fgets(recmsg, BUFLEN, stdin) == (char *) EOF)
84.exit(0);
85./* 发送消息 */86.if (sendto
87.(sockfd, recmsg, strlen(recmsg), 0,
88.(struct sockaddr *) &peeraddr,
89.sizeof(struct sockaddr_in)) < 0) {
90.printf("sendto error!/n");
91.exit(3);
92.}
93.printf("'%s' send ok/n", recmsg);
94.}
95.}
96.
组播服务器端程序源代码为：
1.#include <sys/types.h> 2.#include <sys/socket.h> 3.#include <arpa/inet.h> 4.#include <stdio.h> 5.#include <stdlib.h> 6.#include <string.h> 7.#include <netdb.h> 8.#include <errno.h> 9.10.#define BUFLEN 255 11./*********************************************************************
12.*filename: mcastserver.c
13.*purpose: 演示组播编程的基本步骤，组播服务器端，关键在于加入组
14.*tidied by: zhoulifa([email protected]) 周立发(http://zhoulifa.bokee.com)
15.Linux爱好者 Linux知识传播者 SOHO族 开发者 最擅长C语言
16.*date time:2007-01-25 13:20:00
17.*Note: 任何人可以任意复制代码并运用这些文档，当然包括你的商业用途
18.* 但请遵循GPL
19.*Thanks to: Google.com
20.*Hope:希望越来越多的人贡献自己的力量，为科学技术发展出力
21.* 科技站在巨人的肩膀上进步更快！感谢有开源前辈的贡献！
22.*********************************************************************/23.int main(int argc, char **argv)
24.{
25.struct sockaddr_in peeraddr;
26.struct in_addr ia;
27.int sockfd;
28.char recmsg[BUFLEN + 1];
29.unsigned int socklen, n;
30.struct hostent *group;
31.struct ip_mreq mreq;
32.33./* 创建 socket 用于UDP通讯 */34.sockfd = socket(AF_INET, SOCK_DGRAM, 0);
35.if (sockfd < 0) {
36.printf("socket creating err in udptalk/n");
37.exit(1);
38.}
39.40./* 设置要加入组播的地址 */41.bzero(&mreq, sizeof(struct ip_mreq));
42.if (argv[1]) {
43.if ((group = gethostbyname(argv[1])) == (struct hostent *) 0) {
44.perror("gethostbyname");
45.exit(errno);
46.}
47.} else {
48.printf
49.("you should give me a group address, 224.0.0.0-239.255.255.255/n");
50.exit(errno);
51.}
52.53.bcopy((void *) group->h_addr, (void *) &ia, group->h_length);
54./* 设置组地址 */55.bcopy(&ia, &mreq.imr_multiaddr.s_addr, sizeof(struct in_addr));
56.57./* 设置发送组播消息的源主机的地址信息 */58.mreq.imr_interface.s_addr = htonl(INADDR_ANY);
59.60./* 把本机加入组播地址，即本机网卡作为组播成员，只有加入组才能收到组播消息 */61.if (setsockopt
62.(sockfd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq,
63.sizeof(struct ip_mreq)) == -1) {
64.perror("setsockopt");
65.exit(-1);
66.}
67.68.socklen = sizeof(struct sockaddr_in);
69.memset(&peeraddr, 0, socklen);
70.peeraddr.sin_family = AF_INET;
71.if (argv[2])
72.peeraddr.sin_port = htons(atoi(argv[2]));
73.else74.peeraddr.sin_port = htons(7838);
75.if (argv[1]) {
76.if (inet_pton(AF_INET, argv[1], &peeraddr.sin_addr) <= 0) {
77.printf("Wrong dest IP address!/n");
78.exit(0);
79.}
80.} else {
81.printf("no group address given, 224.0.0.0-239.255.255.255/n");
82.exit(errno);
83.}
84.85./* 绑定自己的端口和IP信息到socket上 */86.if (bind
87.(sockfd, (struct sockaddr *) &peeraddr,
88.sizeof(struct sockaddr_in)) == -1) {
89.printf("Bind error/n");
90.exit(0);
91.}
92.93./* 循环接收网络上来的组播消息 */94.for (;;) {
95.bzero(recmsg, BUFLEN + 1);
96.n = recvfrom(sockfd, recmsg, BUFLEN, 0,
97.(struct sockaddr *) &peeraddr, &socklen);
98.if (n < 0) {
99.printf("recvfrom err in udptalk!/n");
100.exit(4);
101.} else {
102./* 成功接收到数据报 */103.recmsg[n] = 0;
104.printf("peer:%s", recmsg);
105.}
106.}
107.}
108.
编译程序用下列命令：
gcc -Wall mcastclient.c -o mcastclient
gcc -Wall mcastserver.c -o mcastserver
运行程序用如下命令：
./mcastserver 230.1.1.1 7838
客户端程序运行命令为：
./mcastclient 230.1.1.1 7838 192.168.100.1 12345
本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/lbsljn/archive/2008/12/13/3511065.aspx