Linux本地套接字（Unix域套接字）----SOCK_DGRAM方式

目录

简述

创建服务端代码：

创建客户端代码

接收函数封装

发送封装

服务端测试main函数

客户端测试main函数

编译运行结果

---

简述

这里介绍一下Linux进程间通信的socket方式---Local socket。这篇主要是介绍下SOCK_DGRAM方式的通信，即数据包的方式（与UDP类似），面向无连接。

这个代码是我刚开始学的时候写的，代码比较简单，适合初学，学习最快的方式就是直接拿源码修改、编译运行、调试。

完整源代码：https://gitee.com/fensnote/demo_code/tree/master/Linux/unix_socket

创建服务端代码：

int startServer()
{
    int iRet;

	TSockAddrUn serv_unadr;
	TSockAddrIn serv_inadr;
	TSockAddr   *pSockAddr = NULL;

	bzero(&serv_unadr,sizeof(serv_unadr));
	bzero(&serv_inadr,sizeof(serv_inadr));

	serv_unadr.sun_family = AF_UNIX;
	strcpy(serv_unadr.sun_path,UNIX_SOCKET_PATH);

	pSockAddr = (TSockAddr *)&serv_unadr;

	signal(SIGPIPE, SIG_IGN);

	/* 创建本地socket */
	sockFd = socket(AF_UNIX, SOCK_DGRAM, 0);//数据包方式
	if ( sockFd <= 0)
	{
	    perror("socket error");
	    return sockFd;
	}

	/* 绑定监听口 */
    int flag = 1;
    iRet = setsockopt(sockFd, SOL_SOCKET, SO_REUSEADDR, &flag, sizeof(flag));

    setSocketAttr(sockFd);

    unlink(UNIX_SOCKET_PATH);
	iRet = bind(sockFd, pSockAddr, sizeof(TSockAddr));
	if (iRet != 0)
	{
	    perror("bind error");
		close(sockFd);
		return -1;
	}

    return sockFd;
}

创建客户端代码

面向无连接的方式，和服务端的代码差别不大：

int InitUdpClient()
{

	TSockAddrUn unadr;
	TSockAddr   *pSockAddr = NULL;

	bzero(&unadr,sizeof(unadr));

	char tmpPath[] = "/tmp/unix_XXXX";
	char *tmpName = mktemp(tmpPath);

	unadr.sun_family = AF_LOCAL;
	strcpy(unadr.sun_path, tmpName);

	pSockAddr = (TSockAddr *)&unadr;

	/* 创建本地socket */
	sockFd = socket(AF_LOCAL, SOCK_DGRAM, 0);//数据包方式
	if ( sockFd <= 0)
	{
	    perror("CUdpClient:: socket error");
	    return sockFd;
	}

	unlink(tmpPath);

	/* 绑定监听口 */
    //setSocketAttr(sockFd);
	int iRet = bind(sockFd,pSockAddr, sizeof(TSockAddr));
	if (iRet != 0)
	{
	    perror("bind error");
		close(sockFd);
		return -1;
	}

    return sockFd;
}

接收函数封装

//返回0 超时  timeOut-超时时间
int UnixRead(char *recvBuf, int len, int timeOut)
{
	int nRead = readable_timeo(sockFd, timeOut);
	if ( nRead <= 0 )
	{
		printf("UnixRead, read time out!\n");
		return 0;
	}

	pSockAddr = (TSockAddr *)&unClientaddr;
	socklen  = sizeof(TSockAddrUn);

	bzero(recvBuf, len);

	nRead = recvfrom(sockFd, recvBuf, len, 0, pSockAddr, &socklen);
	if ( nRead <= 0 )
	{
		if ( (EAGAIN == errno) || (EINTR == errno))
		{
			return 0;   //接收连接超时
		}

		perror("UnixRead read error:");
	}

	return nRead;
}

发送封装

int UnixSend(const void *data, int len)
{
	TSockAddrUn unadr;
	TSockAddr   *pSockAddr = NULL;

	bzero(&unadr,sizeof(unadr));

	unadr.sun_family = AF_LOCAL;
	strcpy(unadr.sun_path, UNIX_SOCKET_PATH);

	pSockAddr = (TSockAddr *)&unadr;
	socklen_t socklen  = sizeof(TSockAddrUn);

	return sendto(sockFd, data, len, 0, pSockAddr, socklen);
}

服务端测试main函数

int main()
{
	startServer();
	int nRead = 0;

	char recvBuf[1024] = {0}; 	

	while(1)
	{
		nRead = UnixRead(recvBuf, 1024, 5);
		if ( nRead <= 0 )
		{
			continue;
		}
		else
		{
			printf("recv %d data: %s\n",nRead, recvBuf);
			const char *sendMsg = "svr ack!";
			UnixSend(sendMsg, strlen(sendMsg));
		}

		sleep(1);
	}

	return 0;
}

客户端测试main函数

 int main(  )
 {
	 int sockFd = InitUdpClient();

	 int nRead = 0;

	 const char *sendMsg = "hello";
	 char recvBuf[1024] = {0};
	 while(1)
	 {

		nRead = UnixSend(sendMsg, strlen(sendMsg));
		printf("send %d data: %s\n", nRead, sendMsg);

		nRead = UnixRead(recvBuf, 1024, 5);
		printf("recv %d data: %s\n", nRead, recvBuf);
		sleep(2);
	 }
	 return 0;
 }

编译运行结果

左边是服务端，右边是客户端。