t113-c-udp篇

之前学习了tcp发送数据，但是效果很不理想，那么试一下用udp会怎么样，学习一下udp是怎么用用的吧

看例子

例子是在百问网下载的，

server

client

这个有点奇怪，有点看不懂

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

/* socket
 * connect
 * send/recv
 */

#define SERVER_PORT 8888

int main(int argc, char **argv)
{
	int iSocketClient;
	struct sockaddr_in tSocketServerAddr;
	
	int iRet;
	unsigned char ucSendBuf[1000];
	int iSendLen;
	int iAddrLen;

	if (argc != 2)
	{
		printf("Usage:\n");
		printf("%s <server_ip>\n", argv[0]);
		return -1;
	}

	iSocketClient = socket(AF_INET, SOCK_DGRAM, 0);

	tSocketServerAddr.sin_family      = AF_INET;
	tSocketServerAddr.sin_port        = htons(SERVER_PORT);  /* host to net, short */
 	//tSocketServerAddr.sin_addr.s_addr = INADDR_ANY;
 	if (0 == inet_aton(argv[1], &tSocketServerAddr.sin_addr))
 	{
		printf("invalid server_ip\n");
		return -1;
	}
	memset(tSocketServerAddr.sin_zero, 0, 8);

#if 0
	iRet = connect(iSocketClient, (const struct sockaddr *)&tSocketServerAddr, sizeof(struct sockaddr));	
	if (-1 == iRet)
	{
		printf("connect error!\n");
		return -1;
	}
#endif

	while (1)
	{
		if (fgets(ucSendBuf, 999, stdin))
		{
#if 0
			iSendLen = send(iSocketClient, ucSendBuf, strlen(ucSendBuf), 0);
#else
			iAddrLen = sizeof(struct sockaddr);
			iSendLen = sendto(iSocketClient, ucSendBuf, strlen(ucSendBuf), 0,
			                      (const struct sockaddr *)&tSocketServerAddr, iAddrLen);

#endif
			if (iSendLen <= 0)
			{
				close(iSocketClient);
				return -1;
			}
		}
	}
	
	return 0;
}