用c语言创建服务器,实现文件上传下载功能程序
时间: 2023-06-07 19:10:50 浏览: 55
好的,我会尝试回答您的问题。首先,您需要了解如何在C语言中创建一个Socket来进行通信。Socket可以让您通过互联网连接其他计算机。
对于服务器,您需要创建一个监听Socket来接收来自客户端的请求,并创建一个新的Socket来处理每个客户端的请求。一旦您接收到客户端的请求,您可以使用文件I/O函数在服务器和客户端之间发送文件。
以下是一个简单的C语言示例代码,可以帮助您开始编写您的程序:
```
#include <stdio.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>
#define PORT 8080
#define BUFFER_SIZE 1024
int main(int argc, char const *argv[]) {
int server_fd, new_socket, valread, file_size, client_sockfd;
struct sockaddr_in address;
char buffer[BUFFER_SIZE] = {0};
char filename[BUFFER_SIZE] = {0};
FILE* fp;
// Create socket
if ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0) {
perror("Socket creation failed.");
exit(EXIT_FAILURE);
}
// Bind socket to port
address.sin_family = AF_INET;
address.sin_addr.s_addr = INADDR_ANY;
address.sin_port = htons(PORT);
if (bind(server_fd, (struct sockaddr*)&address, sizeof(address)) < 0) {
perror("Bind failed.");
exit(EXIT_FAILURE);
}
// Listen for incoming connections
if (listen(server_fd, 3) < 0) {
perror("Listen failed.");
exit(EXIT_FAILURE);
}
// Accept incoming connections
while (1) {
if ((new_socket = accept(server_fd, (struct sockaddr*)&address, (socklen_t*)&client_sockfd))<0) {
perror("Accept failed.");
exit(EXIT_FAILURE);
}
// Receive filename
valread = read(new_socket, filename, BUFFER_SIZE);
// Open file
fp = fopen(filename, "rb");
if (fp == NULL) {
perror("File not found.");
exit(EXIT_FAILURE);
}
// Get file size
fseek(fp, 0, SEEK_END);
file_size = ftell(fp);
rewind(fp);
// Send file size
send(new_socket, &file_size, sizeof(file_size), 0);
// Send file
while(!feof(fp)) {
fread(buffer, sizeof(char), BUFFER_SIZE, fp);
send(new_socket, buffer, BUFFER_SIZE, 0);
memset(buffer, 0, BUFFER_SIZE);
}
fclose(fp);
close(new_socket);
}
return 0;
}
```
这段代码创建了一个Socket,监听来自客户端的请求,并在收到请求后发送文件。请注意,此代码只是示例,并且不一定安全或完整。您需要添加一些错误检查以确保您的程序能够安全地处理所有情况。