[摘抄-Socket-学习中]UDP通信基础代码-server端

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <sys/socket.h>

#include <netinet/in.h>

#include <arpa/inet.h>

#include <netdb.h>

#include <unistd.h>

int port = 10005;

int SendInfo(char* ip, char* info)

{

int sockfd;

int len = 0;

struct sockaddr_in adr_srvr;

bzero(&adr_srvr, sizeof(adr_srvr));

adr_srvr.sin_family = AF_INET;

adr_srvr.sin_addr.s_addr = inet_addr(ip);

adr_srvr.sin_port = htons(port);

sockfd = socket(AF_INET, SOCK_DGRAM, 0);

if(sockfd == -1)

{

printf("连接失败，ip=%s,port=%d\n",ip,port);

return -1;

}

len = sendto(sockfd, info, strlen(info), 0, (struct sockaddr*)&adr_srvr, sizeof(adr_srvr));

if(len < 0)

{

printf("发送数据失败！\n");

return -1;

}

printf("回复成功！info=%s\n",info);

close(sockfd);

}

int test()

{

int sockfd;

int len;

int z;

char buf[256];

struct sockaddr_in adr_inet;

struct sockaddr_in adr_clnt;

printf("等待Client段传送数据....\n");

bzero(&adr_inet, sizeof(adr_inet));

adr_inet.sin_family = AF_INET;

//adr_inet.sin_addr.s_addr = inet_addr("218.244.145.161");

//adr_inet.sin_addr.s_addr = inet_addr("192.168.207.40");

adr_inet.sin_addr.s_addr = htonl(INADDR_ANY);

adr_inet.sin_port = htons(port);

len = sizeof(adr_clnt);

sockfd = socket(AF_INET, SOCK_DGRAM, 0);

if(sockfd == -1)

{

perror("socket error");

exit(1);

}

z = bind(sockfd, (struct sockaddr *)&adr_inet, sizeof(adr_inet));

if(z == -1)

{

perror("bind error");

exit(1);

}

printf("监听和绑定成功....\n");

while(1)

{

z = recvfrom(sockfd, buf, sizeof(buf), 0, (struct sockaddr *)&adr_clnt, (socklen_t *)&len);

if(z < 0)

{

perror("recvfrom error");

printf("recv error\n");

exit(1);

}

buf[z] = 0;

char* ip = inet_ntoa(adr_clnt.sin_addr);

printf("ip=%s,port=%d\n",ip, ntohs(adr_clnt.sin_port));

printf("接收数据：");

for(int i=0; i<z;i++)

{

printf("%02X ",buf[i]);

}

printf(" 数据长度：%d\n",z);

//取出本地IP地址

struct sockaddr_in serv;

char serv_ip[20];

int serv_len = sizeof(serv);

getsockname(sockfd, (struct sockaddr *)&serv,(socklen_t *) &serv_len);

inet_ntop(AF_INET, &serv.sin_addr, serv_ip, sizeof(serv_ip));

printf("本地地址：%s\n",serv_ip);

SendInfo(ip, buf);

}

close(sockfd);

}

int main(int argc, char *argv[])

{

test();

return 0;

}

编译：g++ main.c -o udp