IPv4套接口地址结构
struct sockaddr_in {
uint8_t sin_len;4
sa_family_t sin_family;4
in_port_tsin_port;2
struct in_addrsin_addr;4
char sin_zero[8];8
};
通用地址结构
struct sockaddr {
uint8_t sin_len;
sa_family_t sin_family;
char sa_data[14];//14
};
服务端
//查看8001端口
netstat -na | grep 8001
int main(void){int sockfd=0;
/*socket 创建文件描述符*/
sockfd=socket(AF_INET,SOCK_STREAM,0);
if(sockfd == -1){
perror("fun socket\n");
exit(0);
}
/*bind 绑定地址和端口*/
/*struct sockaddr {
sa_family_t sa_family;
char sa_data[14];
struct sockaddr_in {
uint8_t sin_len; 4
sa_family_t sin_family; 4
in_port_t sin_port; 2
struct in_addr sin_addr; 4
char sin_zero[8]; 8
};
}*/
struct sockaddr_in srvaddr;
srvaddr.sin_family = AF_INET;
srvaddr.sin_port = htons(8001);
srvaddr.sin_addr.s_addr = inet_addr("127.0.0.1");
if( bind(sockfd, (struct sockaddr *) &srvaddr,sizeof(srvaddr)) < 0){
perror("fun bind\n");
exit(0);
}
/*listen 开启监听 同时监听数量
调用listen之后sockfd变成被动套接字,只能接受链接不能主动发送
*/
if(listen(sockfd,SOMAXCONN) < 0){
perror("fun listen\n");
exit(0);
}
/*accept */
struct sockaddr_in peeraddr;
socklen_t peerlen=sizeof(peeraddr);
unsigned int conn = 0;
conn = accept(sockfd,(struct sockaddr *) &peeraddr,(socklen_t *) &peerlen);
if(conn == -1){
perror("fun accept\n");
exit(0);
}
printf("perradd:%s\n perrport:%d\n",inet_ntoa(peeraddr.sin_addr),ntohs(peeraddr.sin_port));
char revbuf[1024] = {0};
/*read write*/
while(1){
int ret = read(conn,revbuf,sizeof(revbuf));
if(ret == 0){
//收到0数据包说明对方已经关闭
printf("对方已经关闭\n");
exit(0);
}
else if(ret < 0){
perror("读数据失败\n");
exit(0);
}
fputs(revbuf,stdout);//服务器收到数据,打印屏幕
write(conn,revbuf,ret);
}
return 0;
}
客户端
int main(void){
int sockfd=0;
/*socket 创建文件描述符*/
sockfd=socket(AF_INET,SOCK_STREAM,0);
if(sockfd == -1){
perror("fun socket\n");
exit(0);
}
/*bind 绑定地址和端口*/
/*struct sockaddr {
sa_family_t sa_family;
char sa_data[14];
struct sockaddr_in {
uint8_t sin_len; 4
sa_family_t sin_family; 4
in_port_t sin_port; 2
struct in_addr sin_addr; 4
char sin_zero[8]; 8
};
}*/
struct sockaddr_in srvaddr;
srvaddr.sin_family = AF_INET;
srvaddr.sin_port = htons(8001);
srvaddr.sin_addr.s_addr = inet_addr("127.0.0.1");
if(connect(sockfd,(struct sockaddr *)&srvaddr,sizeof(srvaddr)) < 0){
perror("connect error\n");
exit(0);
}
char revbuf[1024] = {0};
char sendbuf[1024] = {0};
while(fgets(sendbuf,sizeof(sendbuf),stdin) != NULL){
//向服务器上写数据
write(sockfd,sendbuf,sizeof(sendbuf));
//从服务器上读数据
read(sockfd,revbuf,sizeof(revbuf));
//打印到屏幕
fputs(revbuf,stdout);
memset(revbuf,0,sizeof(revbuf));
memset(sendbuf,0,sizeof(sendbuf));
}
close(sockfd);
return 0;
}
