粘包
只有tcp协议才会发送粘包,udp不会发生。发送端发送数据,接收端不知道应该如何去接收,造成的一种数据混乱的现象
import subprocess r = subprocess.Popen('ls',shell=True,stdout=subprocess.PIPE,stderr=subprocess.PIPE) # subprocess.Popen(cmd,shell=True,subprocess.stdout,subprocess.stderr) # cmd : 代表系统命令 # shell = True 代表这条命令是 系统命令,告诉操作系统,将cmd当成系统命令去执行 # stdout 是执行完系统命令之后,用于保存结果的一个管道 # stderr 是执行完系统命令之后,用于保存错误结果的一个管道 stdout = r.stdout.read().decode('gbk') stderr = r.stderr.read().decode('gbk') print('正确的返回结果:',stdout) print('错误的返回结果:',stderr) print('错误的返回结果:',stderr)
客户端发送要执行命令
服务器执行,执行完将结果返回给客户端
客户端拿到结果呈现到用户眼前
服务端
import socket import subprocess sk = socket.socket() sk.bind(('127.0.0.1', 8080)) sk.listen() conn, addr = sk.accept() while 1: cmd = conn.recv(1024).decode('utf-8') r = subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE) stdout = r.stdout.read() stderr = r.stderr.read() if stderr: conn.send(stderr) else: conn.send(stdout) conn.close() sk.close()
客户端
import socket sk = socket.socket() sk.connect_ex(('127.0.0.1', 8080)) while 1: cmd = input('请输入一个命令>>>') sk.send(cmd.encode('utf-8')) result = sk.recv(102) result = result.decode('gbk') print(result) sk.close()
socket 实现 ssh
a = '邹' print(len(a)) # 1 print(len(a.encode())) # 3 转换为bytes一个汉字三个字符
客户端
import socket client = socket.socket() client.connect(('localhost', 9999)) while True: msg = input(">>:").strip() if len(msg) == 0: # 输入的为空 continue client.send(msg.encode("utf-8")) data = client.recv(1024) print("recv:", data.decode()) client.close()
服务端
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() # 执行输入的命令，decode转换为字符串 if len(cmd_res) == 0: cmd_res = 'cmd has no out' conn.send(cmd_res.encode('utf-8')) # 转为utf-8发过去
当我们在客户端执行 ifconfig 命令时，第一次返回的不全（1024字节），在执行 ls 命令时，返回的是 ifconfig 剩下的命令（1024字节），如下
>>:ifconfig recv: lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384 options=1203<RXCSUM,TXCSUM,TXSTATUS,SW_TIMESTAMP> inet 127.0.0.1 netmask 0xff000000 inet6 ::1 prefixlen 128 inet6 fe80::1%lo0 prefixlen 64 scopeid 0x1 nd6 options=201<PERFORMNUD,DAD> gif0: flags=8010<POINTOPOINT,MULTICAST> mtu 1280 stf0: flags=0<> mtu 1280 ap1: flags=8802<BROADCAST,SIMPLEX,MULTICAST> mtu 1500 options=400<CHANNEL_IO> ether b2:9c:4a:c4:34:e7 media: autoselect status: inactive en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500 options=400<CHANNEL_IO> ether 90:9c:4a:c4:34:e7 inet6 fe80::18f2:9b2f:4496:675e%en0 prefixlen 64 secured scopeid 0x6 inet 192.168.31.110 netmask 0xffffff00 broadcast 192.168.31.255 nd6 options=201<PERFORMNUD,DAD> media: autoselect status: active p2p0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 2304 options=400<CHANNEL_IO> ether 02:9c:4a:c4:34:e7 media: autoselect status: inactive awdl0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1484 opti >>:ls recv: ons=400<CHANNEL_IO> ether e2:3f:ba:ac:28:1d inet6 fe80::e03f:baff:feac:281d%awdl0 prefixlen 64 scopeid 0x8 nd6 options=201<PERFORMNUD,DAD> media: autoselect status: active llw0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500 options=400<CHANNEL_IO> ether e2:3f:ba:ac:28:1d inet6 fe80::e03f:baff:feac:281d%llw0 prefixlen 64 scopeid 0x9 nd6 options=201<PERFORMNUD,DAD> media: autoselect status: active en2: flags=8963<UP,BROADCAST,SMART,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500 options=460<TSO4,TSO6,CHANNEL_IO> ether 1e:66:6c:14:0d:c4 media: autoselect <full-duplex> status: inactive en1: flags=8963<UP,BROADCAST,SMART,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500 options=460<TSO4,TSO6,CHANNEL_IO> ether 1e:66:6c:14:0d:c5 media: autoselect <full-duplex> status: inactive en3: flags=8963<UP,BROADCAST,SMART,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500 options=460<TSO4,TSO6,CHANNEL_IO> ether 1e:66:6c:14:0d:c1 media: autoselect <full-duplex> status: inactive en4: flags=8963<U
全部接收
先判断需要接收的数据，然后接收的和实际的对比，如果小于实际的，继续接收，否则，打印出接收的大小和命令
客户端
import socket client = socket.socket() client.connect(('localhost', 9999)) while True: msg = input(">>:").strip() if len(msg) == 0: continue client.send(msg.encode("utf-8")) data_size = client.recv(1024) # 接收命令的长度 print('需要接收的数据大小：', data_size) client.send('开始发吧'.encode('utf-8')) # 处理黏包 reve_size = 0 reve_data = b'' while reve_size < int(data_size.decode()): # data_size是byte类型 data = client.recv(1024) reve_size += len(data) # 每次收到的有可能小于1024，所以必须用len判断 reve_data += data else: print('接收到的大小：', reve_size) print(reve_data.decode()) client.close()
服务端
import socket, os 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() # 执行输入的命令，decode转换为字符串 print('数据的大小：', len(cmd_res)) if len(cmd_res) == 0: cmd_res = 'cmd has no out' conn.send(str(len(cmd_res.encode())).encode('utf-8')) # 数字不能encode。cmd_res.encode()将汉字转换成3个字节，不转发送的大小和接收的大小不一样 conn.recv(1024) # 处理黏包 conn.send(cmd_res.encode('utf-8')) # 转为 utf-8发过去
