python学习--for Mac 问题解决：socket.gaierror: [Errno -2] Name or service not known

在Mac电脑上利用bottle搭建简单web服务器，以实现mac版本的网络调试助手。

主程序从csdn下载，下载地址为：http://download.csdn.net/detail/yuanhuamanjing/9383142，推测为win运行环境。调试后的服务器程序main.py如下：

#-*-coding:utf8;-*- #qpy:2 #qpy:webapp:TCPUDP #qpy://localhost:8081/ import sys, os, re, json import socket, threading, time, Queue from bottle import route, run, redirect from bottle import static_file, template if True: #Android QPython os.chdir(os.path.dirname(__file__)) sys.path.append('/data/data/com.hipipal.qpyplus/files/lib/python2.7/site-packages/websocket_server-0.4-py2.7.egg') sys.path.append('/data/data/com.hipipal.qpyplus/files/lib/python2.7/site-packages/CherryPy-3.8.0-py2.7.egg') @route('/') @route('/<info>') def index(info=''): net.sock_close() return template('index.html', ip=net.local_ip, info=info) @route('/tcpServ/<ip>/<port:int>') def tcpServ(ip, port): if net.sock_open('tcpServ', (ip, port)): return template('main.html', title='TCP服务器') else: redirect('/' + 'TCP服务器开启失败') @route('/tcpClin/<ip>/<port:int>') def tcpClin(ip, port): if net.sock_open('tcpClin', (ip, port)): return template('main.html', title='TCP客户端') else: redirect('/' + '连接到TCP服务器失败') @route('/udpServ/<ip>/<port:int>') def udpServ(ip, port): if net.sock_open('udpServ', (ip, port)): return template('main.html', title='UDP服务器') else: redirect('/' + 'UDP服务器开启失败') @route('/udpClin/<ip>/<port:int>') def udpClin(ip, port): if net.sock_open('udpClin', (ip, port)): return template('main.html', title='UDP客户端') else: redirect('/' + '连接到UDP服务器失败') @route('/static/<filepath:path>') def server_static(filepath): return static_file(filepath, root='./static/') @route('/__exit') def __exit(): threading.Thread(target=websocketServer.server.shutdown).start() class TCPUDP(object): def __init__(self): self.local_ip = socket.gethostbyname(socket.gethostname()) self.hexShow = False self.hexSend = False threading.Thread(target=self.sock_recv).start() threading.Thread(target=self.sock_listen).start() def sock_open(self, mode, addr): self.mode, self.addr = mode, addr if self.mode == 'tcpServ': self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) try: self.sock.bind(addr) self.sock.listen(10) except Exception: return False else: return True elif self.mode == 'tcpClin': self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) try: self.sock.connect(addr) except Exception: return False else: return True elif self.mode == 'udpServ': self.sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) try: self.sock.bind(addr) except Exception: return False else: return True elif self.mode == 'udpClin': self.sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) return True def sock_send(self, str): map = json.loads(str) if map['type'] == 'cmd': if map.has_key('hexShow'): self.hexShow = map['hexShow'] elif map.has_key('hexSend'): self.hexSend = map['hexSend'] else: str = map['data'] if self.mode == 'tcpServ': if hasattr(self, 'clinSock'): self.clinSock.send(str) elif self.mode == 'tcpClin': self.sock.send(str) elif self.mode == 'udpServ': if hasattr(self, 'clinAddr'): self.sock.sendto(str, self.clinAddr) elif self.mode == 'udpClin': self.sock.sendto(str, self.addr) def sock_recv(self): while True: try: if self.mode == 'tcpServ': self.clinSock.setblocking(False) data = self.clinSock.recv(1024) elif self.mode == 'tcpClin': self.sock.setblocking(False) data = self.sock.recv(1024) elif self.mode == 'udpServ': self.sock.setblocking(False) data, addr = self.sock.recvfrom(1024) elif self.mode == 'udpClin': self.sock.setblocking(False) data, addr = self.sock.recvfrom(1024) except Exception as ex: pass else: if self.mode == 'udpServ': self.clinAddr = addr print data if hasattr(websocketServer, 'client'): websocketServer.send_message(data) time.sleep(0.1) def sock_close(self): try: self.sock.shutdown(socket.SHUT_RDWR) except Exception: pass try: self.sock.close() except Exception: pass if hasattr(self, 'clinSock'): delattr(self, 'clinSock') if hasattr(self, 'clinAddr'): delattr(self, 'clinAddr') def sock_listen(self): while 1: try: sock, addr = self.sock.accept() except Exception: pass else: self.clinSock = sock time.sleep(5) class WebsocketServer(object): def __init__(self): import websocket_server self.server = websocket_server.WebsocketServer(13254) self.server.set_fn_new_client(self.websocket_new_client) self.server.set_fn_message_received(self.message_received) threading.Thread(target=self.server.run_forever).start() def websocket_new_client(self, client, server): self.client = client def message_received(self, client, server, message): net.sock_send(message) def send_message(self, msg): self.server.send_message(self.client, msg) if __name__ == '__main__': net = TCPUDP() websocketServer = WebsocketServer() #建立socket run(host='localhost', port='8081', debug=True) #启动本地net assistant

运行时“socket.gethostbyname(socket.gethostname())“语句报错，提示：“socket.gaierror: [Errno -8] Name or service not known”。百度后发现针对mac电脑的问题解答很少，参考网页链接http://www.th7.cn/Program/Python/201605/865623.shtml，原文内容摘抄如下：

该错误的原因是/etc/hostname文件写的hostname 没有写在/etc/hosts里， 加上就好了 。 比如添加 “127.0.0.1 myname” 到hosts最后一行， 即可。

socket.gethostname()读取/etc/hostname中的name； socket.gethostbyname(name)是通过name来提取/etc/hosts里和name对应的ip 。如果hosts里没有对应的name，肯定就要抛出错误。

因此前往/etc文件夹，发现本机无hostname文件，有hosts文件。将hosts文件备份（重要事情说三遍：务必牢记修改系统文件前必须备份，以免发生意外！务必牢记修改系统文件前必须备份，以免发生意外！务必牢记修改系统文件前必须备份，以免发生意外！）打开新的hosts文件，发现hosts文件内容仅有一行localhost记录：

127.0.0.1 localhost

在终端内打开python模式，利用如下代码查询本机hostname，这里举例为“xxMacBookPro.local”：

import socket socket.gethostname()

注：本机hostname的另一种查看方式是在系统偏好设置内，选择共享选项即可，如下图：

添加hosts文件内容如下：

127.0.0.1 localhost 127.0.0.1 xxMacBookPro.local 127.0.0.1 xxMacBookPro

再此运行程序即可成功启动web服务器。

附修改后的运行文件（去除bootstrap.min.css等内容，提高网页加载速度），下载地址为http://download.csdn.net/detail/qiaokelinaicha/9803586： 1. main.py 2. index.html 3. main.html

文件运行顺序为： 1.运行main.py，启动本地web服务器，主页地址为http://localhost:8081/，网页自动跳转至index.html； 2.选择相应的运行模式，tcp服务器模式时输入本机服务器ip地址和端口号；tcp客户端模式时输入监听服务器ip地址和端口号；udp模式与tcp模式对应。选择“开始监听”按钮并成功建立socket后，网页跳转至main.html，自动接收消息，也可按需发送自定义消息。