服务器端:
#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <string.h>
#define PORT 8888
#define IP "192.168.250.100"
#define ERR_MSG(msg) do{\
fprintf(stdout, "%d", __LINE__);\
perror(msg);\
}while(0)
int main(int argc, const char *argv[])
{
//创建udp服务器
//创建套接字
int ufd = socket(AF_INET, SOCK_DGRAM, 0);
if(ufd < 0)
{
ERR_MSG("socket");
return -1;
}
puts("socket success");
//填充服务器的IP和端口
struct sockaddr_in sin;
sin.sin_family = AF_INET;
sin.sin_port = htons(PORT); //端口号
sin.sin_addr.s_addr = inet_addr(IP); //IP
//绑定IP地址和端口号
if(bind(ufd, (struct sockaddr *)&sin, sizeof(sin)) < 0)
{
ERR_MSG("bind");
return -1;
}
puts("bind success");
char buf[128] = "";
//如果想知道数据包从谁那发过来
//需要定义地址数据结构体和长度来接收
struct sockaddr_in cin;
socklen_t addrlen;
while(1)
{
//接收数据
//if(recvfrom(ufd, buf, sizeof(buf), 0, NULL, NULL) < 0)
if(recvfrom(ufd, buf, sizeof(buf), 0, (struct sockaddr *)&cin, &addrlen) < 0)
{
ERR_MSG("recvfrom");
return -1;
}
puts("recvfrom success");
//终端显示数据
printf("%s : %d buf:%s\n", inet_ntoa(cin.sin_addr), ntohs(cin.sin_port), buf);
//发送数据
bzero(buf, sizeof(buf));
strcat(buf, "---");
if(sendto(ufd, buf, sizeof(buf), 0, (struct sockaddr *)&cin, addrlen) < 0)
{
ERR_MSG("sendto");
return -1;
}
puts("sendto success");
}
//关闭套接字
close(ufd);
return 0;
}
客户端:
#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <string.h>
#define PORT 8888
#define IP "192.168.250.100"
#define ERR_MSG(msg) do{\
fprintf(stdout, "%d", __LINE__);\
perror(msg);\
}while(0)
int main(int argc, const char *argv[])
{
//创建套接字
int sfd = socket(AF_INET, SOCK_DGRAM, 0);
if(sfd < 0)
{
ERR_MSG("socket");
return -1;
}
puts("socket success");
//填充服务器IP和端口
struct sockaddr_in sin;
sin.sin_family = AF_INET;
sin.sin_port = htons(8888);
sin.sin_addr.s_addr = inet_addr("192.168.250.100");
struct sockaddr_in cin;
socklen_t addrlen;
char buf[128] = "";
while(1)
{
//客户端发送数据包给服务器
printf("请输入:");
bzero(buf, sizeof(buf));
fgets(buf, sizeof(buf), stdin);
buf[strlen(buf) - 1] = 0;
if(sendto(sfd, buf, sizeof(buf), 0, (struct sockaddr *)&sin, sizeof(sin)) < 0)
{
ERR_MSG("sendto");
return -1;
}
puts("sendto success");
//接收数据包
if(recvfrom(sfd, buf, sizeof(buf), 0, NULL, 0) < 0)
{
ERR_MSG("recvfrom");
return -1;
}
puts("recvfrom success");
printf("%s",buf);
}
//关闭套接字
close(sfd);
return 0;
}
实验现象: