华为云代理商：c语言实现ftp多线程服务器

luotuoemo • 2024年7月25日 02:36 • 华为云 • 阅读 472

可以。下面是一个用C语言实现的多线程FTP服务器的基本代码示例：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <pthread.h>

#define PORT 21
#define MAX_CLIENTS 10
#define BUFFER_SIZE 1024

void* handle_client(void* client_socket);

int main() {
    int server_socket, client_socket;
    struct sockaddr_in server_addr, client_addr;
    socklen_t client_addr_len = sizeof(client_addr);
    pthread_t threads[MAX_CLIENTS];
    int client_count = 0;

    server_socket = socket(AF_INET, SOCK_STREAM, 0);
    if (server_socket < 0) {
        perror("Socket creation failed");
        exit(EXIT_FAILURE);
    }

    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = INADDR_ANY;
    server_addr.sin_port = htons(PORT);

    if (bind(server_socket, (struct sockaddr*)&server_addr, sizeof(server_addr)) < 0) {
        perror("Bind failed");
        close(server_socket);
        exit(EXIT_FAILURE);
    }

    if (listen(server_socket, 3) < 0) {
        perror("Listen failed");
        close(server_socket);
        exit(EXIT_FAILURE);
    }

    printf("FTP server is listening on port %d...n", PORT);

    while ((client_socket = accept(server_socket, (struct sockaddr*)&client_addr, &client_addr_len)) >= 0) {
        if (client_count >= MAX_CLIENTS) {
            printf("Maximum clients reached. Rejecting client.n");
            close(client_socket);
        } else {
            printf("Accepted client %dn", client_socket);
            pthread_create(&threads[client_count++], NULL, handle_client, (void*)&client_socket);
        }
    }

    close(server_socket);
    return 0;
}

void* handle_client(void* client_socket) {
    int socket = *(int*)client_socket;
    char buffer[BUFFER_SIZE];
    int bytes_read;

    strcpy(buffer, "220 Welcome to the FTP serverrn");
    send(socket, buffer, strlen(buffer), 0);

    while ((bytes_read = read(socket, buffer, BUFFER_SIZE)) > 0) {
        buffer[bytes_read] = '';
        printf("Received: %s", buffer);

        // Simple echo back
        send(socket, buffer, bytes_read, 0);
    }

    close(socket);
    printf("Client disconnectedn");
    pthread_exit(NULL);
}

这个示例代码实现了一个简单的多线程FTP服务器，允许多个客户端连接，并回显客户端发送的消息。以下是代码的一些关键点：