组播发送和组播接收的源代码例子

组播原理这里就不介绍了， 我博客里有介绍组播原理的详细的文章。

这里只是实现一个小例子， 一个 send.cpp 一个recv.cpp文件。

编译后生成2个进程， 一个接收一个发送。

Sender.cpp 文件内容如下：

#include <stdlib.h> #include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> #include <time.h> #include <string.h> #include <stdio.h> #include <unistd.h> #define HELLO_PORT 12345 #define HELLO_GROUP "225.0.0.37" int main(int argc, char *argv[]) { struct sockaddr_in addr; int fd, cnt; struct ip_mreq mreq; char *message="Hello, World!"; /* create what looks like an ordinary UDP socket */ if ((fd=socket(AF_INET,SOCK_DGRAM,0)) < 0) { perror("socket"); exit(1); } /* set up destination address */ memset(&addr,0,sizeof(addr)); addr.sin_family=AF_INET; addr.sin_addr.s_addr=inet_addr(HELLO_GROUP); addr.sin_port=htons(HELLO_PORT); /* now just sendto() our destination! */ while (1) { if (sendto(fd,message, strlen(message), 0, (struct sockaddr *) &addr, sizeof(addr)) < 0) { perror("sendto"); exit(1); } sleep(1); } }

Recver.cpp 文件内容如下：

#include <stdlib.h> #include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> #include <time.h> #include <string.h> #include <stdio.h> #include <unistd.h> #define HELLO_PORT 12345 #define HELLO_GROUP "225.0.0.37" #define MSGBUFSIZE 256 int main(int argc, char *argv[]) { struct sockaddr_in addr; int fd, nbytes,addrlen; struct ip_mreq mreq; char msgbuf[MSGBUFSIZE]; u_int yes=1; /*** MODIFICATION TO ORIGINAL */ /* create what looks like an ordinary UDP socket */ if ((fd=socket(AF_INET,SOCK_DGRAM,0)) < 0) { perror("socket"); exit(1); } /**** MODIFICATION TO ORIGINAL */ /* allow multiple sockets to use the same PORT number */ if (setsockopt(fd,SOL_SOCKET,SO_REUSEADDR,&yes,sizeof(yes)) < 0) { perror("Reusing ADDR failed"); exit(1); } /*** END OF MODIFICATION TO ORIGINAL */ /* set up destination address */ memset(&addr,0,sizeof(addr)); addr.sin_family=AF_INET; addr.sin_addr.s_addr=htonl(INADDR_ANY); /* N.B.: differs from sender */ addr.sin_port=htons(HELLO_PORT); /* bind to receive address */ if (bind(fd,(struct sockaddr *) &addr,sizeof(addr)) < 0) { perror("bind"); exit(1); } /* use setsockopt() to request that the kernel join a multicast group */ mreq.imr_multiaddr.s_addr=inet_addr(HELLO_GROUP); mreq.imr_interface.s_addr=htonl(INADDR_ANY); if (setsockopt(fd,IPPROTO_IP,IP_ADD_MEMBERSHIP,&mreq,sizeof(mreq)) < 0) { perror("setsockopt"); exit(1); } /* now just enter a read-print loop */ while (1) { addrlen=sizeof(addr); if ((nbytes=recvfrom(fd,msgbuf,MSGBUFSIZE,0, (struct sockaddr *) &addr,(socklen_t*)&addrlen)) < 0) { perror("recvfrom"); exit(1); } puts(msgbuf); } return 0; }

Makefie 文件如下 ：

CC = gcc CXX = g++ CFLAGS = -Wall -D_DEBUG -DDEBUG -g -O0 LDFLAGS = MODULE_INC = -I/usr/include MODULE_LIB = -L/usr/lib CFLAGS += $(MODULE_INC) LDFLAGS += $(MODULE_LIB) SENDOBJS = Sender.o RECVOBJS = Recver.o TARGET = Sender Recver all: $(TARGET) Sender: $(SENDOBJS) $(CXX) -o $@ $^ $(LDFLAGS) Recver: $(RECVOBJS) $(CXX) -o $@ $^ $(LDFLAGS) clean: rm -f *.o rm -f $(TARGET) rm -f http/*.o # make rule %.o : %.c $(CC) $(CFLAGS) -c $^ -o $@ %.o : %.cpp $(CC) $(CFLAGS) -c $^ -o $@

编译方法直接

make

下来执行

./Sender

./Recver

即可看到输出的结果。。。。