nginx基础篇学习

linux网络编程之UDP编程

• UDP编程模型
• • • 服务端
    • 客户端
  • tcp与udp的区别

UDP编程模型

服务端

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

int main(){
	//1. 创建socket 		
	int serverFd = socket(AF_INET,SOCK_DGRAM,0);
	if(-1  ==  serverFd) printf("创建socket失败:%m\n"),exit(-1);
	printf("创建socket成功!\n");				
	//2. 构建服务器协议地址族	
	struct sockaddr_in  addr = {0};
	addr.sin_family =   AF_INET;//和socket函数第一个参数一致
	addr.sin_addr.s_addr = inet_addr("192.168.249.135");//把字符串转成整型
	addr.sin_port = htons(9999);//端口号			
	//3. 绑定
	int r = bind(serverFd,(struct sockaddr*)&addr,sizeof addr);
	if(-1  ==  r) printf("绑定失败:%m\n"),close(serverFd),exit(-1);
	printf("绑定成功!\n");	
	//4. 通信
	char buff[256];

	//用来存储客户端协议地址族
	struct sockaddr_in  cAddr = {0};
	int cLen = sizeof cAddr;
	while(1){
		r = recvfrom(serverFd,buff,255,0,
		(struct sockaddr*)&cAddr,&cLen);//和read一样
		if(r>0){
			buff[r] = 0;//添加'\0'
			printf("客户端%s发来的数据>>%s\n",
				inet_ntoa(cAddr.sin_addr),buff);

			sendto(serverFd,"妖怪，吃俺老孙一棒",
				strlen("妖怪，吃俺老孙一棒"),0,
				(struct sockaddr*)&cAddr,sizeof cAddr);
		}
	}

}

客户端

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

int main(){
	//1. 创建socket 		
	int serverFd = socket(AF_INET,SOCK_DGRAM,0);
	if(-1  ==  serverFd) printf("创建socket失败:%m\n"),exit(-1);
	printf("创建socket成功!\n");				
	//2. 构建服务器协议地址族	
	struct sockaddr_in  addr = {0};
	addr.sin_family =   AF_INET;//和socket函数第一个参数一致
	addr.sin_addr.s_addr = inet_addr("192.168.249.135");//把字符串转成整型
	addr.sin_port = htons(9999);//端口号			
	//3. 通信
	char buff[256];
	int r;
	char temp[256];
	int len = sizeof addr;
	while(1){
		memset(buff,0,256);
		printf("请输入>>");
		scanf("%s",buff);
		r = sendto(serverFd,buff,strlen(buff),0,
			(struct sockaddr*)&addr,sizeof addr);
		printf("r:%d\n",r);

		r = recvfrom(serverFd,temp,255,0,
			(struct sockaddr*)&addr,&len);
		if(r > 0){
			temp[r] = 0;
			printf("服务器说:%s\n",temp);
		}
	}



}

tcp与udp的区别