UDP服务器客户端相互通信

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <errno.h>
#include <arpa/inet.h>

#define PORT 3333

int main()
{
int sockfd;
struct sockaddr_in server_addr;
struct sockaddr_in client_addr;
int addrlen = sizeof(struct sockaddr);
int addrinlen = sizeof(struct sockaddr_in);
int recvbytes;
char buf[512];
char buf1[1024] = {0};

if((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
{
fprintf(stderr, "socket error:%s\n", strerror(errno));
exit(1);
}

bzero(&server_addr, sizeof(struct sockaddr_in));
server_addr.sin_family = AF_INET;
server_addr.sin_addr.s_addr = htonl(INADDR_ANY);
server_addr.sin_port = htons(PORT);

if(bind(sockfd, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0)
{
fprintf(stderr, "bind error:%s\n", strerror(errno));
exit(1);
}
while(1)
{
memset(buf, 0, sizeof(buf));
if((recvbytes = recvfrom(sockfd, buf, 512, 0, (struct sockaddr *)&client_addr, &addrinlen)) < 0)
{
fprintf(stderr, "recvfrom error:%s\n", strerror(errno));
exit(1);
}
buf[recvbytes] = '\0';
printf("receive from client is %s", buf);

printf("Please input:");
fgets(buf1, 1024, stdin);
sendto(sockfd, buf1, 1024, 0, (struct sockaddr *)&client_addr, sizeof(struct sockaddr));
}
close(sockfd);

return 0;
}

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <errno.h>

#define PORT 3333

int main()
{
int sockfd;
struct sockaddr_in server_addr;
struct sockaddr_in client_addr;
int addrlen = sizeof(struct sockaddr);
int addrinlen = sizeof(struct sockaddr_in);
char buf[1024] = "hello world";
char buf1[1024];

if((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
{
fprintf(stderr, "socket error:%s\n", strerror(errno));
exit(1);
}

bzero(&server_addr, sizeof(struct sockaddr_in));
server_addr.sin_family = AF_INET;
//server_addr.sin_addr.s_addr = inet_addr("192.168.1.222");
server_addr.sin_addr.s_addr = htonl(INADDR_ANY);
server_addr.sin_port = htons(PORT);

while(1)
{
printf("Please client input:");
fgets(buf, 1024, stdin);

if(sendto(sockfd, buf, sizeof(buf), 0, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0)
{
fprintf(stderr, "sendto error:%s\n", strerror(errno));
//perror("sendto");
exit(1);
}

memset(buf1, 0, sizeof(buf1));
bzero(&client_addr, sizeof(struct sockaddr_in));

if(recvfrom(sockfd, buf1, sizeof(buf1), 0, (struct sockaddr *)&client_addr, &addrlen) < 0)
{
fprintf(stderr, "client recvfrom error:%s\n", strerror(errno));
exit(1);
}
printf("receive from server:%s\n", buf1);

}
close(sockfd);

return 0;

}