python Socket Programming Based on TCP Protocol

Socket Programming Based on TCP Protocol

Realize telephone communication as an example, here is the transfer of characters, you can try to send 1 file

#  Server side 
import socket
# 1.  Accord with TCP Protocol mobile phone 
server = socket.socket(socket.AF_INET,socket.SOCK_STREAM) # TCP
# 2.  Binding mobile phone number  1 Servers , If we use our own computer as a server, , Use your own IP Address 
server.bind(('127.0.0.1',8000)) # 127.0.0.1  On behalf of the local 
# server.bind(('192.168.11.251',8000)) 
server.listen(5) #  Semi-connection pool   Can be received at the same time 5 Clients 
# 3.  Waiting for client connection 
print('start...')
#  Link loop 
while True:
#  Communication loop 
conn,client_addr = server.accept()
while True:
try:
# 4.  Receive information  receive
data = conn.recv(1024) #  How many bytes are received at a time , If changed to 10, Client input dir,( Can be found in cmd Input in  dir, See what you get ) , What will happen , The next blog will talk about the problem of sticky packages , And how to deal with the problem of sticky package 
print(data)
# 5.  Back message 
conn.send(data.upper())
except ConnectionAbortedError:
continue
except ConnectionResetError:
break

#  Client 1
import socket
# 1.  Create conformance TCP Protocol mobile phone 
client = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
# 2.  Dial 
client.connect(('127.0.0.1',8000))
while True:
msg = input('please enter your msg') # dir
# 3.  Send a message 
client.send(msg.encode('utf8'))
# 4.  Receive a message 
data = client.recv(1024)
print(data)

#  Client 2
import socket
# 1.  Create conformance TCP Protocol mobile phone 
client = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
# 2.  Dial 
client.connect(('127.0.0.1',8000))
# msg = input('please enter your msg>>>')
# 3.  Send a message 
client.send('hello'.encode('utf8'))
client.send('world'.encode('utf8'))
# 4.  Receive information 
data = client.recv(1024)
print(data)

Simulate ssh remote execution command (linux system)

# ssh Server side 
import socket
import subprocess
server = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
server.bind(('192.168.11.251',8000)) #  This is my machine , The client can be someone else's machine 
server.listen(5)
print('start...')
while True:
conn,cient_addr = server.accept()
print(client_addr) #  It's printed from someone else's machine IP
while True:
try:
cmd = conn.recv(1024) # dir
print(cmd)
#  Help you execute cmd Command , Then save the execution results in the pipeline 
pipeline = subprocess.Popen(cmd.decode('utf8'),
shell = True,
stderr = subprocess.PIPE, # std  Standard 
stdout = subprocess.PIPE)
stderr = pipeline.stderr.read()
stdout = pipeline.stdout.read()
conn.send(stderr)
conn.send(stdout)
except ConnectionResetError:
break

# ssh Client 
import socket
# 1. Create conformance TCP Protocol mobile phone 
client = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
# 2.  Dial 
client.connect(('192.168.11.210',8000))
while True:
msg = input('please enter your msg') # dir
# 3.  Send a message 
client.send(msg.encode('utf8'))
# 4.  Receive a message 
data = client.recv(10)
print(data.decode('gbk')) #  In mac It may be on the computer 'utf8'

The most effective way to learn is to have input and output, so that what you learn can really be useful