mcast.c

自己编写的一个组播发送

#include <stdio.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>
#include <sys/time.h>
#include <sys/ioctl.h>
#include <netinet/in.h>
#include <arpa/inet.h>

int main(int argc,char **argv)	{
	int send_sockfd;
	int send_buf_size=220*1024;
	struct sockaddr_in mcast_addr;
	int mcast_addr_len;
	FILE *fp;
	char *sendFile="/home/jackie/TestMtv.mpg";
	int bufSize=3.5*1024;
	char buf[bufSize];
	int Msize=1024*1024; //1 Mbytes
	double sum=0.0;
	int counter=0;
	int num_bytes;

	send_sockfd=socket(AF_INET,SOCK_DGRAM,0);
	bzero(&mcast_addr,sizeof(struct sockaddr_in));
	mcast_addr.sin_family=AF_INET;
//	mcast_addr.sin_addr.s_addr=inet_addr("234.1.1.13");
	inet_pton(AF_INET, "234.1.1.13",&mcast_addr.sin_addr);
	mcast_addr.sin_port=htons(1234);
	mcast_addr_len=sizeof(mcast_addr);
	
	setsockopt(send_sockfd,SOL_SOCKET,SO_SNDBUF,&send_buf_size,sizeof(int));
	setsockopt(send_sockfd, IPPROTO_IP, IP_MULTICAST_LOOP, (u_char*)0, sizeof(u_char));
	int reuseaddr=1;
	setsockopt(send_sockfd, SOL_SOCKET, SO_REUSEADDR, &reuseaddr, sizeof(int));

	if((fp=fopen(sendFile,"rb"))==NULL)	{
			printf("\ncannot open file\n");
			exit(0);
	}
	int readSize;
	while(1) {
		readSize=fread(buf,sizeof(char),bufSize,fp);
	//	printf("read %d data\n", readSize);
		if( readSize < 0){
			if(feof(fp)){
				fclose(fp);
				printf("\nfile read completely\n");
				break;
			}
			printf("\nfile read error\n");
			exit(0);
		}
		if ((num_bytes=sendto(send_sockfd, buf, bufSize, 0, (struct sockaddr *)&mcast_addr, sizeof(struct sockaddr))) == -1) {
			printf("send data - error\n");
			exit(0);
		}
		//printf("send %d data\n", num_bytes);
		
		sum += num_bytes;
		if(sum/Msize >= counter) {
			counter++;
			printf("++send %.2fMbytes data stream\n", sum/Msize);
		}
		usleep(1);	
	}
		
}