Python网络通信

day26

网络通信

参考：

http://www.cnblogs.com/yuanchenqi/articles/5692716.html

 

男生是client端，字条是socket（sk），通过sk通信。

socket属于客户端。应用程序两端通过“套接字”向网络发出请求或者应答网络请求。可以把socket理解为通信的把手（hand）。

确定对端IP地址→ 确定应用程序端口 → 确定通讯协议

server下的方法

bind()

listen()

accept()

recv()

send()#传送内容必须为bytes类型

sendall()

close()

client下的方法

connect()

recv()

send()

aendall()

close()

client发送，serve接收

serve.py

import socket

sk = socket.socket()#创建socket

print(sk)

address = ('127.0.0.1', 8000)#本机地址
sk.bind(address)#为socket绑定IP和端口号

sk.listen(3)#限制排队的个数
print('waiting......')
conn, addr = sk.accept()#conn为客户端socket对象
#
# inp = input('>>>')
# conn.send(bytes(inp, 'utf8'))

data = conn.recv(1024)#为什么用conn，而不用sk
print(str(data, 'utf8'))

# conn.close()#关具体对象
# sk.close()#全关

client.py

import socket

sk = socket.socket()

print(sk)
address = ('127.0.0.1', 8000)

sk.connect(address)

#data = sk.recv(1024)#收到的为bytes类型
data = sk.send(bytes('hah', 'utf8'))

#print(str(data, 'utf8'))

运行serve.py

<socket.socket fd=3, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=0, laddr=('0.0.0.0', 0)>
waiting......

waiting，accept()阻塞。

运行client.py

<socket.socket fd=3, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=0, laddr=('0.0.0.0', 0)>

Process finished with exit code 0

serve收到数据“hah”

<socket.socket fd=3, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=0, laddr=('0.0.0.0', 0)>
waiting......
hah

Process finished with exit code 0

client接收，serve发送

serve.py

import socket

sk = socket.socket()#创建socket

print(sk)

address = ('127.0.0.1', 8000)#本机地址
sk.bind(address)#为socket绑定IP和端口号

sk.listen(3)#限制排队的个数
print('waiting......')
conn, addr = sk.accept()#conn为客户端socket对象

inp = input('>>>')
conn.send(bytes(inp, 'utf8'))

# data = conn.recv(1024)#为什么用conn，而不用sk
# print(str(data, 'utf8'))

# conn.close()#关具体对象
# sk.close()#全关

client.py

import socket

sk = socket.socket()

print(sk)
address = ('127.0.0.1', 8000)

sk.connect(address)

data = sk.recv(1024)#收到的为bytes类型
#data = sk.send(bytes('hah', 'utf8'))

print(str(data, 'utf8'))

运行serve.py

<socket.socket fd=3, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=0, laddr=('0.0.0.0', 0)>
waiting......

运行client.py

<socket.socket fd=3, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=0, laddr=('0.0.0.0', 0)>

在serve命令行输入hello

<socket.socket fd=3, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=0, laddr=('0.0.0.0', 0)>
waiting......
>>>hello

Process finished with exit code 0

client命令行收到数据。

<socket.socket fd=3, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=0, laddr=('0.0.0.0', 0)>
hello

Process finished with exit code 0

不间断聊天

client.py

import socket

sk = socket.socket()

print(sk)
address = ('127.0.0.1', 8000)
sk.connect(address)

while True:
    inp = input('>>>')
    if inp == 'exit':
        break
    sk.send(bytes(inp, 'utf8'))

    data = sk.recv(1024)
    print(str(data, 'utf8'))

sk.close()
#print(sk)

serve.py

import socket

sk = socket.socket()#创建socket

print(sk)

address = ('127.0.0.1', 8000)#本机地址
sk.bind(address)#为socket绑定IP和端口号

sk.listen(3)#限制排队的个数
print('waiting......')
#conn, addr = sk.accept()#conn为客户端socket对象

while True:
    conn, addr = sk.accept()
    print(addr)    #client打开则接收
    while True:
        #收
        try:
            data = conn.recv(1024)#为什么用conn，而不用sk,client关闭时报错误
        except Exception:
            break  #client端停止，他也停止
        print('.......',str(data, 'utf8'))
        if not data:break
        #发
        inp = input('>>>')
        conn.send(bytes(inp, 'utf8'))

sk.close()#全关

不间断聊天，其中client若关闭，新开一个client，serve端还能继续服务。

粘包现象（远程执行命令）

cmd_client.py

import socket

sk = socket.socket()

print(sk)
address = ('127.0.0.1', 8001)
sk.connect(address)

while True:
    inp = input('>>>')
    if inp == 'exit':
        break
    sk.send(bytes(inp, 'utf8'))
    result_len = int(str(sk.recv(1024), 'utf8'))

    sk.sendall(bytes('ok', 'utf8'))#收到长度信息后，告诉server

    data = bytes()#初始化
    while len(data) != result_len: #等于原文件大小，说明接收完
        recv = sk.recv(1024)
        data += recv

    print(str(data, 'utf8'))

sk.close()
#print(sk)

cmd_server.py

import socket
import subprocess
sk = socket.socket()#创建socket

print(sk)

address = ('127.0.0.1', 8001)#本机地址
sk.bind(address)#为socket绑定IP和端口号

sk.listen(3)#限制排队的个数
print('waiting......')
#conn, addr = sk.accept()#conn为客户端socket对象

while True:
    conn, addr = sk.accept()
    print(addr)    #client打开则接收
    while True:
        #收
        try:
            data = conn.recv(1024)#为什么用conn，而不用sk,client关闭时报错误
        except Exception:
            break  #client端停止，他也停止
        print('.......',str(data, 'utf8'))

        if not data:break
        obj = subprocess.Popen(str(data, 'utf8'), shell = True, stdout = subprocess.PIPE)
        cmd_result = obj.stdout.read()#以上执行结果
        #print(cmd_result)
        result_len = bytes(str(len(cmd_result)), 'utf8')


        conn.sendall(result_len)#发
        #先向client发送数据，client若收到则向server发送OK，Server再发送处理结果
        #若连续发送，两个发送内容（长度，处理结果）可能会合并。
        re = conn.recv(1024)#防止粘包
        if str(re, 'utf8') != 'ok':
            break
        #发
        conn.sendall(cmd_result)

        # conn.sendall(result_len)  # 这种方式会发生粘包现象，长度和内容合在一起了
        # conn.sendall(cmd_result)
sk.close()#全关

先执行server.py,再执行client.py,在client中输入命令（dir,pwd,ifconfig等）