代码示例_网络编程_UDP

UDP

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1.　头文件

#pragma once

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <strings.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <arpa/inet.h>

#define IP "192.168.2.150"
#define PORT 9999
#define SIZE 128

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2.　client_udp 

#include "net.h"

int main(void)
{
    //1.创建套接字
    int fd = socket( AF_INET, SOCK_DGRAM, 0);
    if(fd<0){
        perror("socket failed");
        exit(1);
    }


    //2.初始服务器地址
    struct sockaddr_in cli;
    cli.sin_family = AF_INET;
    cli.sin_port = htons(PORT);
    cli.sin_addr.s_addr = inet_addr(IP);


    //3.发送
    char buf[SIZE];
    while(1){
    bzero(buf,SIZE);
    printf("please input :	");
    fgets(buf,SIZE,stdin);
    int ret = sendto( fd,buf,SIZE,0,(struct sockaddr*)&cli,sizeof(cli) );
        if(ret<0){
            perror("send failed");
            exit(1);
        }
    if(!strncmp(buf,"quit",4))
        break;
    }

    //4.关闭
    close(fd);


    return 0 ;
}

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3.　server_udp 

#include "net.h"

int main(void)
{
    //1.创建套接字
    int fd = socket(AF_INET,SOCK_DGRAM,0);
    if(fd<0){
        perror("socket failed");
        exit(1);
    }


    //2.初始本地地址
    struct sockaddr_in ser;
    ser.sin_family = AF_INET;
    ser.sin_port = htons(PORT);
    ser.sin_addr.s_addr=inet_addr(IP);


    //绑定
    if(  bind(fd,(struct sockaddr*)&ser,sizeof(ser)) <0){
        perror("bind failed");
        exit(1);
    }


    //接收
    char buf[SIZE];
    socklen_t len = sizeof(ser);
    while(1){
    bzero(buf,SIZE);
    int ret = recvfrom(fd,buf,SIZE,0,(struct sockaddr*)&ser,&len);
        if(ret<0){
            perror("recvfrom failed");
            exit(1);
        }
        else if(ret==0){
            printf("客户端下线...");
            break;
        }
        else if(ret>0){
            printf("server : %s",buf);
            if(!strncmp(buf,"quit",4))
            break;
        }
    }

    return 0 ;
}

测试：

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success ！