socket2

import socket
client = socket.socket()

#client.connect(('192.168.16.200',9999))
client.connect(('localhost',9999))

while True:
    cmd = input(">>:").strip()
    if len(cmd) == 0: continue
    client.send(cmd.encode("utf-8"))
    cmd_res_size = client.recv(1024) ##接受命令结果的长度
    print("命令结果大小:",cmd_res_size)
    received_size = 0
    received_data = b''
    while received_size < int(cmd_res_size.decode()) :
        data = client.recv(1024)
        received_size += len(data) #每次收到的有可能小于1024，所以必须用len判断
        #print(data.decode())
        received_data += data
    else:
        print("cmd res receive done...",received_size)
        print(received_data.decode())


client.close()

import socket ,os,time
server = socket.socket()
server.bind(('localhost',9999) )

server.listen()

while True:
    conn, addr = server.accept()
    print("new conn:",addr)
    while True:
        print("等待新指令")
        data = conn.recv(1024)
        if not data:
            print("客户端已断开")
            break
        print("执行指令:",data)
        cmd_res = os.popen(data.decode()).read() #接受字符串，执行结果也是字符串
        print("before send",len(cmd_res))
        if len(cmd_res) ==0:
            cmd_res = "cmd has no output..."

        conn.send( str(len(cmd_res.encode())).encode("utf-8")    )     #先发大小给客户端
        time.sleep(0.5)
        conn.send(cmd_res.encode("utf-8"))
        print("send done")
        #os.path.isfile()
        #os.stat("sock")
server.close()

import hashlib
m = hashlib.md5()