Python服务器开发三：Socket

Python服务器开发三：Socket

socket是操作系统中I/O的延续，它可以使进程和机器之间的通信成为可能。socket可以看成一个标准的文件描述符。不同的是文件需要用open()函数打开，而socket用socket()

函数建立.recv()、send()函数和read()、write()函数极为相似。

TCP一般通过accept()来为每个连接的客户端建立一个新的scoket。UDP一般只是使用一个单一的socket，完全依靠recvfrom()返回的值来判断该往哪里发送响应。

 

客户端：

1、建立一个socket：

//SOCK_STREAM表示TCP，SOCK_DGRAM表示UDP，AF_INET表示IPv4

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

2、连接socket

连接socket需要一个tuple参数，来提供IP和端口号：

s.connect((“www.example.com”, 80))

3、

#!/usr/bin/env pythonimport socketprint "Creating socket...",
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
print "done."print "Looking up port number...",
port = socket.getservbyname('http', 'tcp')
print "done."print "Connecting to remote host on port %d..." % port,
s.connect(("www.google.com", port))
print "done."#获取本身的IP和端口号
print "Connected from", s.getsockname()
#获取远程的IP和端口号
print "Connected to", s.getpeername()

 

文件类对象：

import socket, sysport = 70
host = sys.argv[1]
filename = sys.argv[2]s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((host, port))
fd = s.makefile('rw', 0)fd.write(filename + "\r\n")for line in fd.readlines():sys.stdout.write(line)

高级接口：

import urllib, sysf = urllib.urlopen(sys.argv[1])
while 1:buf = f.read(2048)if not len(buf):breaksys.stdout.write(buf)

 

 

服务器端：

1、建立一个连接：

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

2、设置socket选项：

//socket 端口可立即复用
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)

3、绑定socket：

s.bind((host, port))

4、监听：

s.listen(1)

5、接受连接：

while 1:clientsock, clientaddr = s.accept()print "Got connection from", clientsock.getpeername()clientsock.close()

6、

#!/usr/bin/env pythonimport socket, tracebackhost = ''                               # Bind to all interfaces
port = 51423s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.bind((host, port))
#这里设定每次最多只有一个等候处理的请求，真正的服务器会设置一个很高的数字。
s.listen(1)while 1:try:clientsock, clientaddr = s.accept()except KeyboardInterrupt:raiseexcept:traceback.print_exc()continue# Process the connectiontry:print "Got connection from", clientsock.getpeername()# Process the request hereexcept (KeyboardInterrupt, SystemExit):raiseexcept:traceback.print_exc()# Close the connectiontry:clientsock.close()except KeyboardInterrupt:raiseexcept:traceback.print_exc()

使用UDP：

#!/usr/bin/env pythonimport socket, tracebackhost = ''                               # Bind to all interfaces
port = 51423s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.bind((host, port))while 1:try:message, address = s.recvfrom(8192)print "Got data from", address# Echo it backs.sendto(message, address)except (KeyboardInterrupt, SystemExit):raiseexcept:traceback.print_exc()