ftp_server.py

'''
ftp 文件服务器
'''
from socket import *
import os 
import sys
import time
import signal  

#文件库路径
FILE_PATH = "/home/tarena/code/"
HOST = '0.0.0.0'
PORT = 8000
ADDR = (HOST,PORT)

#将文件服务器功能写在类中
class FtpServer(object):
    def __init__(self,connfd):
        self.connfd = connfd

    def do_list(self):
        #获取文件列表
        file_list = os.listdir(FILE_PATH)
        if not file_list:
            self.connfd.send("文件库为空".encode()) 
            return 
        else:
            self.connfd.send(b'OK')
            time.sleep(0.1)

        files = ''
        for file in file_list:
            if file[0] != '.' and \
            os.path.isfile(FILE_PATH + file):
                files = files + file + '#'
        self.connfd.sendall(files.encode())

    def do_get(self,filename):
        try:
            fd = open(FILE_PATH + filename,'rb')
        except:
            self.connfd.send('文件不存在'.encode())
            return 
        self.connfd.send(b'OK')
        time.sleep(0.1)
        #发送文件
        while True:
            data = fd.read(1024)
            if not data:
                time.sleep(0.1)
                self.connfd.send(b'##')
                break
            self.connfd.send(data)
        print("文件发送完毕")
    def do_set(self,filenname):    
        try:
            fd = open(FILE_PATH + filenname,'wb')
        except:
            self.connfd.send('文件已存在'.encode())
            return
        self.connfd.send(b'OK')           
        while True:           
            data = self.connfd.recv(1024).decode()
            if data == '##':                
                break
            fd.write(data.encode())
        fd.close()
        print("%s 接收完毕\n"%filenname)       

#创建套接字,接收客户端连接,创建新的进程
def main():
    sockfd = socket()
    sockfd.setsockopt(SOL_SOCKET,SO_REUSEADDR,1)
    sockfd.bind(ADDR)
    sockfd.listen(5)

    #处理子进程退出
    signal.signal(signal.SIGCHLD,signal.SIG_IGN)
    print("Listen the port 8000...")

    while True:
        try:
            connfd,addr = sockfd.accept()
        except KeyboardInterrupt:
            sockfd.close()
            sys.exit("服务器退出")
        except Exception as e:
            print("服务器异常:",e)
            continue 

        print("已连接客户端:",addr)
        #创建子进程
        pid = os.fork()
        if pid == 0:
            sockfd.close()
            ftp = FtpServer(connfd)
            #判断客户端请求
            while True:
                data = connfd.recv(1024).decode()
                if not data  or data[0] == 'Q':
                    connfd.close()
                    sys.exit("客户端退出")
                elif data[0] == 'L':
                    ftp.do_list()
                elif data[0] == 'G':
                    filename = data.split(' ')[-1]
                    ftp.do_get(filename)
                elif data[0] == 'S':
                    filenname = data.split(' ')[-1]
                    ftp.do_set(filenname)

        else:
            connfd.close()
            continue


if __name__ == "__main__":
    main()