ftp service c源代码

FTP (File Transfer Protocol)服务的C源代码通常涉及客户端和服务器两个部分，用于实现文件的上传和下载功能。以下是一个非常简化的例子，展示了如何创建一个基本的FTP服务器的C源代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>

// FTP server functions
void handle_client(int client_socket) {
    char buffer[1024];
    printf("Accepted connection from %d.\n", client_socket);
    while (true) {
        memset(buffer, 0, sizeof(buffer));
        read(client_socket, buffer, sizeof(buffer)); // Read data
        if (strcmp(buffer, "quit") == 0) break; // Check for quit command
        // Process commands here (e.g., FILE LIST, RETR, STOR)
        write(client_socket, "Command not implemented.\n", strlen("Command not implemented.\n"));
    }
    close(client_socket);
}

int main() {
    int server_socket = socket(AF_INET, SOCK_STREAM, 0);
    struct sockaddr_in server_addr;
    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(21); // FTP default port
    server_addr.sin_addr.s_addr = INADDR_ANY;

    bind(server_socket, (struct sockaddr *)&server_addr, sizeof(server_addr));
    listen(server_socket, 5);

    printf("Server started on port %d.\n", ntohs(server_addr.sin_port));

    while (true) {
        int client_socket = accept(server_socket, NULL, NULL);
        if (client_socket < 0) {
            perror("Error accepting client.");
            continue;
        }
        handle_client(client_socket);
    }

    return 0;
}

这只是一个基础的示例，实际的FTP服务会更复杂，包括错误处理、命令解析、数据传输等，并且通常不会直接嵌入到应用代码中，而是作为单独的服务运行。