socket接受大的数据

socket_server_ssh:

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

server.listen()
while True:
    conn,addr = server.accept()
    print("new conn:",addr)
    while True:
        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
        client_ack = conn.recv(1024)  # wait client to confirm
        conn.send(cmd_res.encode("utf-8"))
        print("send done")
server.close()

socket_server_client:

import  socket
client = socket.socket()
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)
    client.send("准备好接收了，可以发了".encode("utf-8"))
    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
        received_data += data
    else:
        print("cmd res receive done...",received_size)
        print(received_data.decode())

client.close()