Python語言實現FTP訪問服務器文件及下載

服務器代碼:

ftpServer.py

 

import socket
import threading
import os
import struct

# 用戶賬號, 密碼, 主目錄
users = {'1': {'pwd': '1', 'home': r'C:\Users\算法練習'},
         'test2': {'pwd': 'testpwd2', 'home': r'D:\知識圖譜資料'}
         }

def server(conn, addr, home):
    print('新客戶端:' + str(addr))
    os.chdir(home)  # 進入當前用戶主目錄
    while True:
        data = str(conn.recv(100).decode().lower())
        print(data)  # 顯示客戶端輸入的每一條命令
        # 客戶端退出
        if data in ('quit', 'q'):
            break
        # 查看當前文件夾的文件列表
        elif data in ('list', 'ls', 'dir'):
            files = str(os.listdir(os.getcwd()))
            files = files.encode()
            # 先發送字節串大小, 再發送字節串
            conn.send(struct.pack('I', len(files)))
            conn.send(files)
        elif ''.join(data) == 'cd..':
            cwd = os.getcwd()
            newCwd = cwd[:cwd.rindex('\\')]
            # 考慮根目錄的情況
            if newCwd[-1] == ':':
                newCwd += '\\'
            # 限定主目錄
            if newCwd.lower().startswith(home):
                os.chdir(newCwd)
                conn.send(b'ok')
            else:
                conn.send(b'error')
        # 查看當前目錄
        elif data in ('cwd', 'cd'):
            conn.send(str(os.getcwd()).encode())
        elif data.startswith('cd '):
            # 指定最大分割次數,考慮目標文件夾帶有空格的情況
            # 只允許使用相對路徑進行跳轉
            data = data.split(maxsplit=1)
            if len(data) == 2 and os.path.isdir(data[1]) and data[1] != os.path.abspath(data[1]):
                os.chdir(data[1])
                conn.send(b'ok')
            else:
                conn.send(b'error')
        # 下載文件
        elif data.startswith('get '):
            data = data.split(maxsplit=1)
            # 檢查文件是否存在
            if len(data) == 2 and os.path.isfile(data[1]):
                conn.send(b'ok')
                fp = open(data[1], 'rb')
                while True:
                    content = fp.read(4096)
                    # 發送文件結束
                    if not content:
                        conn.send(b'over')
                        break
                    conn.send(content)
                    if conn.recv(10) == b'ok':
                        continue
                fp.close()
            else:
                conn.sen(b'no')
        # 命令無效
        else:
            pass
    conn.close()
    print(addr + '斷開連接')

# 創建socket, 監聽本地端口, 等待客戶端連接
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.bind(('', 10600))
sock.listen(5)
print('等待連接....')
while True:
    conn, addr = sock.accept()
    # 驗證客戶端輸入的用戶名和密碼是否正確
    userId, userPwd = conn.recv(1024).decode().split(',')
    if userId in users and users[userId]['pwd'] == userPwd:
        conn.send(b'ok')
        # 為每個客戶端連接創建並啟動一個線程
        # 參數為連接, 客戶端地震, 客戶端主目錄
        home = users[userId]['home']
        t = threading.Thread(target=server, args=(conn, addr, home))
        t.daemon = True
        t.start()
    else:
        conn.send(b'error')

 

 

客戶端源代碼:

ftpClient.py

 

import socket
import struct
import getpass

def main(serverIP):
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.connect((serverIP, 10600))
    userId = input("請輸入用戶名:")
    userPwd = input("請輸入密碼:")
    message = userId + ',' + userPwd
    sock.send(message.encode())
    login = sock.recv(100)
    # 驗證是否登錄成功
    if login == b'error':
        print('用戶米或者密碼錯誤')
        return
    # 整理編碼大小
    intSize = struct.calcsize('I')
    while True:
        # 接收客戶端命令. 其中##>是命令提示符
        command = input('Command:').lower().split()
        # 沒有輸入任何有效字符, 提前進入下一次循環, 等待用戶繼續輸入
        if not command:
            continue
        # 向服務器發送命令
        command = ' '.join(command)
        sock.send(command.encode())
        # 退出
        if command in ('quit', 'q'):
            break
        # 查看文件列表
        elif command in ('list', 'ls', 'dir'):
            # 先接收字符串帶下, 再根據情況接收合適數量的字節串
            loc_size = struct.unpack('I', sock.recv(intSize))[0]
            files = eval(sock.recv(loc_size).decode())
            for item in files:
                print(item)
        # 切換至上一級目錄
        elif ''.join(command.split()) == 'cd..':
            print(sock.recv(100).decode())
        # 當前工作目錄
        elif command in ('cwd', 'cd'):
            print(sock.recv(1024).decode())
        # 切換至子文件夾
        elif command.startswith('cd '):
            print(sock.recv(100).decode())
        # 從服務器下載文件
        elif command.startswith('get '):
            isFileExist = sock.recv(20)
            # 文件存在則下載,不存在則提示文件不存在
            if isFileExist != b'ok':
                print("file not found")
            else:
                print("downloading", end='')
                fp = open(command.split()[1], 'wb')
                while True:
                    # 顯示進度
                    print('*', end='')
                    data = sock.recv(4096)
                    if data == b'over':
                        break
                    fp.write(data)
                    sock.send(b'ok')
                fp.close()
                print('Download complete')
            # 無效命令
        else:
            print('Command not found')
    sock.close()

if __name__ == '__main__':
    serverIP = '192.168.0.100'
    # 使用正則判斷服務器地址是否為合法的IP地址
    main(serverIP)