网络编程-UDP本地通讯

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

#define ERR_MSG(msg) do{\
	fprintf(stderr, "__%d__:", __LINE__);\
	perror(msg);\
}while(0)

int main(int argc, const char *argv[])
{
	//创建域套接字：报式套接字
	int sfd = socket(AF_UNIX, SOCK_DGRAM, 0);
	if(sfd < 0)
	{
		ERR_MSG("socket");
		return -1;
	}

	//判断套接字文件是否存在
	//如果存在则删除套接字文件
	if(access("./unix", F_OK) == 0)
	{
		if(unlink("./unix") < 0)
		{
			ERR_MSG("unlink");
			return -1;
		}
	}


	//填充服务器的地址信息结构体-->需要绑定到套接字上
	struct sockaddr_un sun;
	sun.sun_family 		= AF_UNIX;
	strcpy(sun.sun_path, "./unix");


	//将地址信息结构体绑定到套接字上
	if(bind(sfd, (struct sockaddr*)&sun, sizeof(sun)) < 0)
	{
		ERR_MSG("bind");
		return -1;
	}
	printf("bind success\n");

	char buf[128] = "";
	struct sockaddr_un cun;
	socklen_t addrlen = sizeof(cun);

	while(1)
	{
		bzero(buf, sizeof(buf));
		//接收数据
		if(recvfrom(sfd, buf, sizeof(buf), 0, (struct sockaddr*)&cun, &addrlen) < 0)
		{
			ERR_MSG("recvfrom");
			return -1;
		}
		
		printf("path:%s|%s\n", cun.sun_path, buf);

		//发送数据--->谁发送给我 我就发还给谁
		strcat(buf, "*-*");
		if(sendto(sfd, buf, sizeof(buf), 0, (struct sockaddr*)&cun, sizeof(cun)) < 0)
		{
			ERR_MSG("sendto");
			return -1;
		}
		printf("sendto success\n");
	}

	//关闭文件描述符
	close(sfd);

	return 0;
}