Linux C Socket处理
相关结构
struct sockaddr_in {
__uint8_t sin_len;
sa_family_t sin_family;
in_port_t sin_port;
struct in_addr sin_addr;
char sin_zero[8];
};
struct sockaddr {
__uint8_t sa_len; /* total length */
sa_family_t sa_family; /* [XSI] address family */
char sa_data[14]; /* [XSI] addr value (actually larger) */
};
服务器
#require <stdio.h>
#require <string.h>
#require <sys/socket.h>
#require <netinet/in.h>
#require <arpa/inet.h>
// 最大数据大小
#define MAXDATASIZE 1024
// 服务器监听端口
#define SERVERPORT 8000
// 最大连接数
#define MAXCONN_NUM 10
int main() {
// 申请socket
int sockfd;
if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
fprintf(stderr, "socket error\n");
return 1;
}
// 服务器地址
struct sockaddr_in server_addr;
memset(&server_addr, 0, sizeof(struct sockaddr));
server_addr.sin_family = AF_INET;
server_addr.sin_port = htons(SERVERPORT);
server_addr.sin_addr.s_addr = INADDR_ANY;
// 将server绑定到socket
if (bind(sockfd, (struct sockaddr *)&server_addr, sizeof(struct sockaddr)) == -1) {
fprintf(stderr, "bind error\n");
return 1;
}
// 监听端口
if (listen(sockfd, MAXCONN_NUM) == -1) {
fprintf(stderr, "listen error\n");
return 1;
}
// 循环接收客户端请求
while (1) {
// 初始化客户端地址
int new_fd;
struct sockaddr_in client_addr;
memset(&client_addr, 0, sizeof(struct sockaddr));
int sin_size = sizeof(struct sockaddr_in);
// 等待客户端连接
if ((new_fd= accept(sockfd, (struct sockaddr *)&client_addr, &sin_size)) == -1) {
fprintf(stderr, "accept error\n");
continue;
}
// 客户端连接成功
printf("new connection: %s:%u\n", inet_ntoa(client_addr.sin_addr), client_addr.sin_port);
// 读取数据
int numbytes;
char buf[MAXDATASIZE];
if ((numbytes = recv(new_fd, buf, MAXDATASIZE, 0)) == -1) {
fprintf(stderr, "recv error\n");
continue;
}
// 打印数据
if (numbytes) {
buf[numbytes] = '\0';
printf("recv: %s\n", buf);
sleep(3);
}
// 发送数据
printf("send: dotcoo\n");
if (send(new_fd, "dotcoo", 7, 0) == -1) {
fprintf(stderr, "send error\n");
continue;
}
// 关闭连接
printf("close connection: %s\n", inet_ntoa(client_addr.sin_addr));
close(new_fd);
}
return 0;
}
客户端
#require <stdio.h>
#require <string.h>
#require <sys/socket.h>
#require <netinet/in.h>
// 最大数据大小
#define MAXDATASIZE 1024
// 服务器地址
#define SERVERIP "127.0.0.1"
// 服务器端口
#define SERVERPORT 8000
int main() {
// 申请socket
int sockfd;
if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
fprintf(stderr, "socket error\n");
return 1;
}
// 服务器地址
struct sockaddr_in server_addr;
memset(&server_addr, 0, sizeof(struct sockaddr));
server_addr.sin_family = AF_INET;
server_addr.sin_port = htons(SERVERPORT);
server_addr.sin_addr.s_addr = inet_addr(SERVERIP);
// 连接到服务器
if (connect(sockfd, (struct sockaddr *)&server_addr, sizeof(struct sockaddr)) == -1) {
fprintf(stderr, "connect error\n");
return 1;
}
// 发送数据
printf("send: server hello\n");
if (send(sockfd, "server hello", 13, 0) == -1) {
fprintf(stderr, "send error\n");
return 1;
}
// 读取数据
int numbytes;
char buf[MAXDATASIZE];
if ((numbytes = recv(sockfd, buf, MAXDATASIZE, 0)) == -1) {
fprintf(stderr, "recv error\n");
return 1;
}
// 打印数据
if (numbytes) {
buf[numbytes] = '\0';
printf("recv: %s\n", buf);
}
// 关闭连接
close(sockfd);
return 0;
}