Python简单服务器程序

这是《Python核心编程（中的文第二版）》的一个习题，题目要求服务器能识别以下命令：

ls 返回服务器程序当前目录

os 返回服务器操作系统的信息

date 得到服务器当前的时间

ls dir 返回目录dir的文件列表

服务器程序：

import time
import os
import datetime

HOST=''
PORT=21234
ADDR=(HOST,PORT)
BUFSIZE=8096

SerSock=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
SerSock.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR,1)
SerSock.bind(ADDR)
SerSock.listen(5)

def process_cmd(cmd):
    print "The command receive from client is:%s"%cmd
    if cmd=='ls':
        curdir=os.curdir
        res=os.listdir(curdir)
    elif cmd=='os':
        res=os.uname()
    elif cmd.startswith('ls'):
        length=len(cmd.split())
        if length==1:
            res="command is illegal"
        elif length==2:
            reqdir=cmd.split()[1]
            try:
                res=os.listdir(reqdir)
            except OSError,e:
                res=e
        else:
            res="argument is illegal"
    elif cmd=='date':
        res=datetime.date.today()
    else:
        res='command is illegal'
    print res
    return str(res)
while True:
    CliSock,addr=SerSock.accept()
    print "...connected from %s:%s"%addr
    while True:
        cmd=CliSock.recv(BUFSIZE)
        if not cmd:
            break
        else:
            res=process_cmd(cmd)
        CliSock.send(res)
    CliSock.close()
SerSock.close()

客户端程序：

#!/usr/bin/python

import socket

HOST='localhost'
PORT=21234
ADDR=(HOST,PORT)
BUFSIZ=8096

CliSock=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
CliSock.connect(ADDR)
print "Please input below command."
print "*************************************"
print "date   ls/ls dir     os"
print "*************************************"
while True:
    cmd=raw_input(">")
    if not cmd:
        continue
    CliSock.send(cmd)
    res=CliSock.recv(BUFSIZ)
    if not res:
        print "response from server error."
    print res

CliSock.close()

执行结果：

Please input below command.
*************************************
date   ls/ls dir     os
*************************************
>date
2015-06-09
>ls
['client_select.py', 'client.py', 'server_select.py', 'chat_server_v1.py', 'server.py', 'daytimeclient.py', 'chat_client_v1.py', 'chat_server_v2.py', 'tsTserv.py', 'tsTclnt.py']
>ls /home
['tmyyss']
>os
('Linux', 'ubuntu', '3.13.0-53-generic', '#89-Ubuntu SMP Wed May 20 10:34:28 UTC 2015', 'i686')
>
>
>
>
>exit
command is illegal
>
>
>q
command is illegal