用select编写文件上传
时间: 2023-08-10 14:16:57 浏览: 41
你可以使用select函数来实现文件上传功能,以下是一个简单的示例代码:
```c
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/select.h>
#include <netinet/in.h>
#define PORT 8080
#define MAX_CLIENTS 5
int main(int argc, char const *argv[])
{
int server_fd, new_socket, client_sockets[MAX_CLIENTS], max_clients = 0;
fd_set readfds;
struct sockaddr_in address;
int addrlen = sizeof(address);
char buffer[1024] = {0};
// 创建套接字
if ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0)
{
perror("socket failed");
exit(EXIT_FAILURE);
}
// 设置套接字绑定的IP和端口
address.sin_family = AF_INET;
address.sin_addr.s_addr = INADDR_ANY;
address.sin_port = htons(PORT);
// 绑定套接字
if (bind(server_fd, (struct sockaddr *)&address, sizeof(address)) < 0)
{
perror("bind failed");
exit(EXIT_FAILURE);
}
// 监听套接字
if (listen(server_fd, 3) < 0)
{
perror("listen failed");
exit(EXIT_FAILURE);
}
// 将服务器套接字添加到fd_set中
FD_ZERO(&readfds);
FD_SET(server_fd, &readfds);
max_clients = server_fd;
while (1)
{
fd_set tmp_fds = readfds;
// 选择就绪的套接字
if (select(max_clients + 1, &tmp_fds, NULL, NULL, NULL) < 0)
{
perror("select failed");
exit(EXIT_FAILURE);
}
// 遍历所有套接字,处理就绪的套接字
for (int i = 0; i <= max_clients; i++)
{
if (FD_ISSET(i, &tmp_fds))
{
// 处理新的客户端连接请求
if (i == server_fd)
{
if ((new_socket = accept(server_fd, (struct sockaddr *)&address, (socklen_t*)&addrlen)) < 0)
{
perror("accept failed");
exit(EXIT_FAILURE);
}
// 将新的客户端套接字添加到fd_set中
FD_SET(new_socket, &readfds);
if (new_socket > max_clients)
{
max_clients = new_socket;
}
printf("New client connected, socket fd is %d, ip is : %s, port : %d\n", new_socket, inet_ntoa(address.sin_addr), ntohs(address.sin_port));
}
// 处理已连接的客户端发来的数据
else
{
int valread;
if ((valread = read(i, buffer, 1024)) == 0)
{
// 客户端关闭连接
close(i);
FD_CLR(i, &readfds);
printf("Client disconnected, socket fd is %d\n", i);
}
else
{
// 处理上传的文件数据
// 这里省略具体的文件处理逻辑
printf("Received file data: %s\n", buffer);
}
}
}
}
}
return 0;
}
```
该示例代码使用select函数来同时处理多个客户端连接,并监听每个客户端套接字上的数据请求。当有数据到来时,程序会读取数据并进行处理。对于文件上传,你需要在程序中添加相应的文件处理逻辑。