一. 模拟ssh

# ===================================== 服务器端 =====================================import socketimport subprocess    # 系统操作server = socket.socket()server.bind(('127.0.0.1',8008))server.listen(5)while True:    print("server is working.....")    conn,addr = server.accept()    # 字节类型    while True:        # 针对window系统        try:            cmd = conn.recv(1024).decode("utf8") # 阻塞            if cmd == b'exit':                break            res=subprocess.Popen(cmd,                             shell=True,                             stderr=subprocess.PIPE,                             stdout=subprocess.PIPE,                             )            # print("stdout",res.stdout.read())            # print("stderr",res.stderr.read().decode("gbk"))            out=res.stdout.read()            err=res.stderr.read()            print("out响应长度",len(out))            print("err响应长度",len(err))            if err:                 import struct                 header_pack = struct.pack("i", len(err))                 conn.send(header_pack)                 conn.send(err)            else:                 #构建报头                 import struct                 header_pack=struct.pack("i",len(out))                 print("header_pack",header_pack)                 # # 发送报头                 conn.send(str(len(out)).encode("utf8"))                 # 发送数据                 conn.send(out)        except Exception as e:            break    conn.close() # ===================================== 客户端 =====================================import socketimport structsk = socket.socket()sk.connect(('127.0.0.1', 8008))while 1:	cmd = input("请输入命令：")	sk.send(cmd.encode('utf-8'))  # 字节	if cmd == "":  # 空字符串无法发送		continue	if cmd == 'exit':		break	header_pack = sk.recv(4)	data_length = struct.unpack("i", header_pack)[0]  # unpack是一个元组	print("data_length", data_length)	data_length = int(sk.recv(1024).decode("utf8"))	print("data_length", data_length)	recv_data_length = 0	recv_data = b""	while recv_data_length < data_length:		data = sk.recv(1024)		recv_data_length += len(data)		recv_data += data	print(recv_data.decode("gbk"))sk.close()

　　

二. hashlib模块

import hashlibmd5=hashlib.md5()md5.update(b"hello")md5.update(b"yuan")print(md5.hexdigest())print(len(md5.hexdigest()))#helloyuan:   d843cc930aa76f7799bba1780f578439#             d843cc930aa76f7799bba1780f578439       # 多次update和单次update结果一样#############################################md5=hashlib.md5()with open("ssh_client.py","rb") as f:    for line in f:        md5.update(line)     # 多次update和单次update结果一样print(md5.hexdigest()) # f.read()

　　

三. struct模块

import structres=struct.pack("i",2934781)print(res)print(len(res))obj=struct.unpack("i",res)print(obj[0])

　　

四. subprocess模块 # windows系统明命令

import subprocessres=subprocess.Popen("dir",                     shell=True,                     stderr=subprocess.PIPE,                     stdout=subprocess.PIPE)print(res.stdout.read().decode("gbk"))