Python开发【第八篇】：socket网络编程

服务端：

1. import socket
2. server = socket.socket()
3. #绑定要监听的端口
4. server.bind(('localhost',6969))
5. #监听
6. server.listen()
7. print("等待连接...")
8. #等待连接，conn就是客户端连过来在服务端为其生成的一个连接实例
9. conn,addr = server.accept()
10. print("连接进行中...")
11. print(conn,addr)
12.  
13. data = conn.recv(1024)
14. print("recv:",data)
15. conn.send(data.upper())
16. server.close()

客户端：

1. import socket
2.  
3. #声明socket类型，同时生产socket连接对象
4. client = socket.socket()
5. client.connect(('localhost',6969))
6. client.send(b"hello world!")
7. data = client.recv(1024)
8. print("recv:",data)
9. client.close()

服务端输出：

1. 等待连接...
2. 连接进行中...
3. <socket.socket fd=328, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=0, laddr=('127.0.0.1', 6969), raddr=('127.0.0.1', 50248)> ('127.0.0.1', 50248)
4. recv: b'hello world!'

客户端输出：

1. recv: b'HELLO WORLD!'

连续发送信息：

服务端：

1. import socket
2. client = socket.socket()
3. client.connect(('localhost',6969))
4. while True:
5.     msg = input(">>:").strip()
6.     client.send(msg.encode("utf-8"))
7.     data = client.recv(1024)
8.     print("recv:",data.decode())
9. client.close()

客户端：

1. import socket
2.  
3. #声明socket类型，同时生产socket连接对象
4. client = socket.socket()
5. client.connect(('localhost',6969))
6. client.send(b"hello world!")
7. # client.send("我要下载".encode("utf-8"))
8. data = client.recv(1024)
9. print("recv:",data)
10. client.close()

在linux上客户端执行命令

服务端：

1. [root@test-c2c-console01 oldboy]# cat socket_server.py
2. #-*-coding:utf-8-*-
3. #_author_="golden"
4. #服务端
5. import socket
6. import os
7.  
8. server = socket.socket()
9. #绑定要监听的端口
10. server.bind(('localhost',6969))
11. #监听，最大连接数
12. server.listen(5)
13. print("等待连接...")
14. while True:
15.     #conn就是客户端连过来在服务端为其生成的一个连接实例
16.     conn,addr = server.accept()
17.     print("连接进行中...")
18.     print(conn,addr)
19.     while True:
20.         data = conn.recv(1024)
21.         print("recv:",data)
22.         if not data:
23.             print("客户端断开！")
24.             break
25.         res = os.popen(data).read()
26.         conn.send(res)
27. server.close()

客户端：

1. [root@test-c2c-console01 oldboy]# cat socket_client.py
2. #-*-coding:utf-8-*-
3. _author_ = "golden"
4. #客户端
5. import socket
6. #声明socket类型，同时生成socket连接对象
7. client = socket.socket()
8. client.connect(('localhost',6969))
9. while True:
10.     msg = raw_input(">>:").strip()
11.     if len(msg) == 0:continue
12.     client.send(msg.encode("utf-8"))
13.     data = client.recv(102400)
14.     print(data.decode())
15.  
16. client.close()

linux发送文件

服务端：

1. [root@test-c2c-console01 oldboy]# cat socket_server.py
2. #-*-coding:utf-8-*-
3. #_author_="golden"
4. #服务端
5. import socket
6. import os
7.  
8. server = socket.socket()
9. #绑定要监听的端口
10. server.bind(('localhost',6969))
11. #监听，最大连接数
12. server.listen(5)
13. print("等待连接...")
14. while True:
15.     #conn就是客户端连过来在服务端为其生成的一个连接实例
16.     conn,addr = server.accept()
17.     print("连接进行中...")
18.     print(conn,addr)
19.     while True:
20.         data = conn.recv(1024)
21.         print("recv:",data)
22.         if not data:
23.             print("客户端断开！")
24.             break
25.         #res = os.popen(data).read()
26.         #conn.send(res)
27.         f = open("move.mkv")
28.         data = f.read()
29.         conn.send(data)
30. server.close()

客户端：

1. [root@test-c2c-console01 oldboy]# cat socket_client.py
2. #-*-coding:utf-8-*-
3. _author_ = "golden"
4. #客户端
5. import socket
6. #声明socket类型，同时生成socket连接对象
7. client = socket.socket()
8. client.connect(('localhost',6969))
9. while True:
10.     msg = raw_input(">>:").strip()
11.     if len(msg) == 0:continue
12.     client.send(msg.encode("utf-8"))
13.     data = client.recv(102400)
14.     #print(data.decode())
15.     f = open("video.avi",'wb')
16.     f.write(data)
17.     f.close()
18.  
19. client.close()

一次最多发送的数据量32768（不同系统有区别）

1. [root@test-c2c-console01 oldboy]# ll *.avi *.mkv
2. -rw-r--r-- 1 root root 681790584 Dec 27 19:26 move.mkv
3. -rw-r--r-- 1 root root 32768 Feb 12 08:47 video.avi

多次发送

服务端：

1. [root@test-c2c-console01 oldboy]# cat socket_server.py
2. #-*-coding:utf-8-*-
3. #_author_="golden"
4. #服务端
5. import socket
6. import os
7.  
8. server = socket.socket() #实例化一个socket
9. #绑定要监听的端口
10. server.bind(('localhost',6969))
11. #监听，最大连接数
12. server.listen(5)
13. print("等待连接...")
14. while True:
15.     #conn就是客户端连过来在服务端为其生成的一个连接实例
16.     conn,addr = server.accept()
17.     print("连接进行中...")
18.     print(conn,addr)
19.     while True:
20.         data = conn.recv(1024)
21.         print("recv:",data)
22.         if not data:
23.             print("客户端断开！")
24.             break
25.         #res = os.popen(data).read()
26.         #conn.send(res)
27.         f = open("move.mkv")
28.         data = f.read()
29.         print(len(data))
30.         conn.send(data)
31. server.close()

客户端：

1. [root@test-c2c-console01 oldboy]# cat socket_client.py
2. #-*-coding:utf-8-*-
3. _author_ = "golden"
4. #客户端
5. import socket
6. #声明socket类型，同时生成socket连接对象
7. client = socket.socket()
8. client.connect(('localhost',6969))
9. f = open("video.avi",'wb')
10. while True:
11.     msg = raw_input(">>:").strip()
12.     if len(msg) == 0:continue
13.     client.send(msg.encode("utf-8"))
14.     data = client.recv(102400)
15.     #print(data.decode())
16.     f.write(data)
17.     f.flush()
18.  
19. client.close()

每交互一次文件的变化：

1. [root@test-c2c-console01 oldboy]# ll
2. total 665832
3. -rw-r--r-- 1 root root 681790584 Dec 27 19:26 move.mkv
4. -rw-r--r-- 1 root root 0 Feb 12 09:08 video.avi
5. [root@test-c2c-console01 oldboy]# ll
6. total 665864
7. -rw-r--r-- 1 root root 681790584 Dec 27 19:26 move.mkv
8. -rw-r--r-- 1 root root 32768 Feb 12 09:08 video.avi
9. [root@test-c2c-console01 oldboy]# ll
10. total 665964
11. -rw-r--r-- 1 root root 681790584 Dec 27 19:26 move.mkv
12. -rw-r--r-- 1 root root 135168 Feb 12 09:08 video.avi
13. [root@test-c2c-console01 oldboy]# ll
14. total 666164
15. -rw-r--r-- 1 root root 681790584 Dec 27 19:26 move.mkv
16. -rw-r--r-- 1 root root 339968 Feb 12 09:09 video.avi
17. [root@test-c2c-console01 oldboy]# ll
18. total 666164
19. -rw-r--r-- 1 root root 681790584 Dec 27 19:26 move.mkv
20. -rw-r--r-- 1 root root 339968 Feb 12 09:09 video.avi

socket实现简单的ssh

服务端：

1. import socket,os
2. server = socket.socket()
3. server.bind(('localhost',9999))
4. server.listen()
5. while True:
6.     conn,addr = server.accept()
7.     print("new conn:",addr)
8.     while True:
9.         data = conn.recv(1024)
10.         if not data:
11.             print("客户端已断开！")
12.             break
13.         print("执行指令：",data)
14.         cmd_res = os.popen(data.decode()).read() #接收字符串，执行结果也是字符串
15.         print("before send ",len(cmd_res))
16.         if len(cmd_res) ==0:
17.             cmd_res = "cmd has no output"
18.         conn.send(str(len(cmd_res.encode())).encode("utf-8"))#先发大小给客户端
19.         conn.send(cmd_res.encode("utf-8"))
20.  
21. server.close()

客户端：

1. import socket
2. client = socket.socket()
3. client.connect(('localhost',9999))
4.  
5. while True:
6.     cmd = input(">>:").strip()
7.     if len(cmd) == 0:continue
8.     client.send(cmd.encode("utf-8"))
9.     cmd_res_size = client.recv(1024)#接收大小
10.     print("结果大小：",cmd_res_size)
11.     received_size = 0
12.     received_data = b''
13.     while received_size < int(cmd_res_size.decode()):
14.         data = client.recv(1024)
15.         received_size += len(data) #每次收到的有可能小于1024，所以必须用len判断
16.         # print(data.decode())
17.         received_data += data
18.     else:
19.         print("cmd res receive done...",received_size)
20.         print(received_data.decode())
21.  
22. client.close()

注意socket粘包问题。

方法一：在多个相连的send之间添加sleep。

1. conn.send(str(len(cmd_res.encode())).encode("utf-8"))#先发大小给客户端
2. time.sleep(0.5)
3. conn.send(cmd_res.encode("utf-8"))

方法二：在每次send之后进行一次交互。

服务端：

1. conn.send(str(len(cmd_res.encode())).encode("utf-8"))#先发大小给客户端client_ack = conn.recv(1024) #wait client to confirm
2. print(client_ack.decode())
3. conn.send(cmd_res.encode("utf-8"))

客户端：

1. cmd_res_size = client.recv(1024)#接收大小
2. client.send("已准备好接收数据！".encode("utf-8"))

socket实现简单的ftp

ftp server：

1、读取文件名

2、检测文件是否存在

3、打开文件

4、检测文件大小

5、发送文件大小给客户端

6、等待客户端确认

7、开始边读边发数据

8、发送md5

服务端：

1. import socket,os,hashlib
2. server = socket.socket()
3. server.bind(("localhost",9999))
4. server.listen()
5. while True:
6.     conn,addr = server.accept()
7.     print("new conn:",addr)
8.     while True:
9.         print("等待指令...")
10.         data = conn.recv(1024)
11.         if not data:
12.             print("客户端已断开！")
13.             break
14.         cmd,filename = data.decode().split()
15.         print(filename)
16.         if os.path.isfile(filename):
17.             f = open(filename,"rb")
18.             m = hashlib.md5()
19.             file_size = os.stat(filename).st_size
20.             conn.send(str(file_size).encode()) #send file size
21.             conn.recv(1024) #wait for ack
22.             for line in f:
23.                 m.update(line)
24.                 conn.send(line)
25.             print("file md5",m.hexdigest())
26.             f.close()
27.             conn.send(m.hexdigest().encode()) #sed med5
28.         print("send done")
29.  
30. server.close()

客户端：

1. import socket,hashlib
2. client = socket.socket()
3. client.connect(('localhost',9999))
4. while True:
5.     cmd = input(">>:").strip()
6.     if len(cmd) == 0:continue
7.     if cmd.startswith("get"):
8.         client.send(cmd.encode())
9.         server_response = client.recv(1024)
10.         print("server_response:",server_response)
11.         client.send(b"read to recv file")
12.         file_total_size = int(server_response.decode())
13.         received_size = 0
14.         filename = cmd.split()[1]
15.         f = open(filename + ".new","wb")
16.         m = hashlib.md5()
17.         while received_size < file_total_size:
18.             if file_total_size - received_size > 1024:
19.                 size = 1024
20.             else:
21.                 size = file_total_size - received_size
22.  
23.             data = client.recv(size)
24.             received_size += len(data)
25.             m.update(data)
26.             f.write(data)
27.             # print(file_total_size,received_size)
28.         else:
29.             new_file_md5 = m.hexdigest()
30.             print("file recv done",received_size,file_total_size)
31.             f.close()
32.         server_file_md5 = client.recv(1024)
33.         print("server file md5:{0},client file md5:{1}".format(server_file_md5,new_file_md5))
34. client.close()

SocketServer

实现并发处理。

The socketserver module simplifies the task of writing network servers.

socketserver常用类型

class socketserver.TCPServer(server_address,RequestHandlerClass,bind_and_activate=True)

This uses the Internet TCP protocol,which provides for continuous streams of data between the client and server.

class socketserver.UDPServer(server_address,RequestHandlerClass,bind_and_activate=True)

This uses datagrams,which are discrete packets of information that may arrive out of order or be lost while in transit.The parameters are the same as for TCPServer.

创建一个socketserver至少分一下几步：

1、You mast create a request handler class by subclassing the BaseRequestHandler class and overriding its handle() method;this method will process incoming requests.

创建一个请求处理类继承BaseRequestHandler，并且重写父类handle()。

2、You mast instantiate one of the server classes,passing it the server's address and the request handler class.

实例化TCPServer，并传递server ip和上述创建的请求处理类给这个TCPServer。

3、Then call the handle_request() or server_forever() method of the server object to process one or many requests.

server.handle_request()：只处理一个请求

server.server_forever()：处理多个请求

4、Call server_close() to close the socket.

服务端：

1. import socketserver
2.  
3. class MyTCPHandler(socketserver.BaseRequestHandler):
4.  
5.     def handle(self):
6.         while True:
7.             try:
8.                 self.data = self.request.recv(1024).strip()
9.                 print("{} wrote :".format(self.client_address[0]))
10.                 print(self.data)
11.                 self.request.send(self.data.upper())
12.             except ConnectionResetError as CR:
13.                 print("err",CR)
14.                 break
15.  
16. if __name__ == "__main__":
17.     HOST,PORT = "localhost",9999
18.     # server = socketserver.TCPServer((HOST,PORT),MyTCPHandler) # 单线程
19.     server = socketserver.ThreadingTCPServer((HOST,PORT),MyTCPHandler) # 多线程，ForkingTCPServer多进程
20.     server.serve_forever()

客户端：

1. import socket
2.  
3. client = socket.socket()
4. client.connect(("localhost",9999))
5. while True:
6.     msg = input(">>:").strip()
7.     if len(msg) == 0:continue
8.     client.send(msg.encode("utf-8"))
9.     data = client.recv(1024)
10.     print("recv:",data.decode())
11. client.close()

开启一个新线程

1. def process_request(self, request, client_address):
2.     """Start a new thread to process the request."""
3.     t = threading.Thread(target = self.process_request_thread,
4.                          args = (request, client_address))
5.     t.daemon = self.daemon_threads
6.     t.start()