#!/usr/bin/env python2.7 # wrp.py - Web Rendering Proxy # A HTTP proxy service that renders the requested URL in to a GIF image associated # with an imagemap of clickable links. This is an adaptation of previous works by # picidae.net and Paul Hammond. __version__ = "1.4" # # This program is based on the software picidae.py from picidae.net # It was modified by Antoni Sawicki http://www.tenox.net/out/#wrp # # This program is based on the software webkit2png from Paul Hammond. # It was extended by picidae.net # # Copyright (c) 2013-2014 Antoni Sawicki # Copyright (c) 2012-2013 picidae.net # Copyright (c) 2004-2013 Paul Hammond # Copyright (c) 2017 Natalia Portillo # # Permission is hereby granted, free of charge, to any person obtaining a copy # of this software and associated documentation files (the "Software"), to deal # in the Software without restriction, including without limitation the rights # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell # copies of the Software, and to permit persons to whom the Software is # furnished to do so, subject to the following conditions: # # The above copyright notice and this permission notice shall be included in # all copies or substantial portions of the Software. # # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN # THE SOFTWARE. # # Configuration options: PORT = 8080 WIDTH = 1024 HEIGHT = 768 ISMAP = "true" WAIT = 1 # sleep for 1 second to allow javascript renders QUALITY = 80 # jpeg image quality 0-100 AUTOWIDTH = True # Check for browser width using javascript import re import random import os import time import string import urllib import socket import SocketServer import SimpleHTTPServer import threading import Queue import sys import logging import StringIO # Request queue (URLs go in here) REQ = Queue.Queue() # Response queue (dummy response objects) RESP = Queue.Queue() # Renders dictionary RENDERS = {} ####################### ### Linux CODEPATH ### ####################### if sys.platform == "linux" or sys.platform == "linux2": try: from PyQt5.QtCore import * from PyQt5.QtGui import * from PyQt5.QtWebKit import * from PyQt5.QtWebKitWidgets import * from PyQt5.QtNetwork import * from PyQt5.QtWidgets import * IsPyQt5 = True except ImportError: from PyQt4.QtCore import * from PyQt4.QtGui import * from PyQt4.QtWebKit import * from PyQt4.QtNetwork import * IsPyQt5 = False # claunia: Check how to use this in macOS logging.basicConfig(filename='/dev/stdout', level=logging.WARN, ) logger = logging.getLogger('wrp') # Class for Website-Rendering. Uses QWebPage, which # requires a running QtGui to work. class WebkitRenderer(QObject): def __init__(self, **kwargs): """Sets default values for the properties.""" if not QApplication.instance(): raise RuntimeError(self.__class__.__name__ + \ " requires a running QApplication instance") QObject.__init__(self) # Initialize default properties self.width = kwargs.get('width', 0) self.height = kwargs.get('height', 0) self.timeout = kwargs.get('timeout', 0) self.wait = kwargs.get('wait', 0) self.logger = kwargs.get('logger', None) # Set this to true if you want to capture flash. # Not that your desktop must be large enough for # fitting the whole window. self.grabWholeWindow = kwargs.get('grabWholeWindow', False) # Set some default options for QWebPage self.qWebSettings = { QWebSettings.JavascriptEnabled : True, QWebSettings.PluginsEnabled : True, QWebSettings.PrivateBrowsingEnabled : True, QWebSettings.JavascriptCanOpenWindows : False } def render(self, url): """Renders the given URL into a QImage object""" # We have to use this helper object because # QApplication.processEvents may be called, causing # this method to get called while it has not returned yet. helper = _WebkitRendererHelper(self) helper._window.resize(self.width, self.height) image = helper.render(url) # Bind helper instance to this image to prevent the # object from being cleaned up (and with it the QWebPage, etc) # before the data has been used. image.helper = helper return image class _WebkitRendererHelper(QObject): """This helper class is doing the real work. It is required to allow WebkitRenderer.render() to be called "asynchronously" (but always from Qt's GUI thread). """ def __init__(self, parent): """Copies the properties from the parent (WebkitRenderer) object, creates the required instances of QWebPage, QWebView and QMainWindow and registers some Slots. """ QObject.__init__(self) # Copy properties from parent for key, value in parent.__dict__.items(): setattr(self, key, value) # Create and connect required PyQt4 objects self._page = CustomWebPage(logger=self.logger) self._view = QWebView() self._view.setPage(self._page) self._window = QMainWindow() self._window.setCentralWidget(self._view) # Import QWebSettings for key, value in self.qWebSettings.iteritems(): self._page.settings().setAttribute(key, value) # Connect required event listeners if IsPyQt5: self._page.loadFinished.connect(self._on_load_finished) self._page.loadStarted.connect(self._on_load_started) self._page.networkAccessManager().sslErrors.connect(self._on_ssl_errors) self._page.networkAccessManager().finished.connect(self._on_each_reply) else: self.connect(self._page, SIGNAL("loadFinished(bool)"), self._on_load_finished) self.connect(self._page, SIGNAL("loadStarted()"), self._on_load_started) self.connect(self._page.networkAccessManager(), SIGNAL("sslErrors(QNetworkReply *,const QList&)"), self._on_ssl_errors) self.connect(self._page.networkAccessManager(), SIGNAL("finished(QNetworkReply *)"), self._on_each_reply) # The way we will use this, it seems to be unesseccary to have Scrollbars enabled self._page.mainFrame().setScrollBarPolicy(Qt.Horizontal, Qt.ScrollBarAlwaysOff) self._page.mainFrame().setScrollBarPolicy(Qt.Vertical, Qt.ScrollBarAlwaysOff) self._page.settings().setUserStyleSheetUrl( QUrl("data:text/css,html,body{overflow-y:hidden !important;}")) # Show this widget # self._window.show() def __del__(self): """Clean up Qt4 objects. """ self._window.close() del self._window del self._view del self._page def render(self, url): """The real worker. Loads the page (_load_page) and awaits the end of the given 'delay'. While it is waiting outstanding QApplication events are processed. After the given delay, the Window or Widget (depends on the value of 'grabWholeWindow' is drawn into a QPixmap """ self._load_page(url, self.width, self.height, self.timeout) # Wait for end of timer. In this time, process # other outstanding Qt events. if self.wait > 0: if self.logger: self.logger.debug("Waiting %d seconds " % self.wait) waitToTime = time.time() + self.wait while time.time() < waitToTime: if QApplication.hasPendingEvents(): QApplication.processEvents() if self.grabWholeWindow: # Note that this does not fully ensure that the # window still has the focus when the screen is # grabbed. This might result in a race condition. self._view.activateWindow() if IsPyQt5: image = QScreen.grabWindow(self._window.winId()) else: image = QPixmap.grabWindow(self._window.winId()) else: if IsPyQt5: image = QWidget.grab(self._window) else: image = QPixmap.grabWidget(self._window) httpout = WebkitRenderer.httpout frame = self._view.page().currentFrame() web_url = frame.url().toString() # Write URL map httpout.write("\n" % (__version__)) httpout.write("\n" % (WebkitRenderer.req_url, web_url)) # Get title httpout.write("") for ttl in frame.findAllElements('title'): httpout.write((u"%s" % ttl.toPlainText()).encode('utf-8', errors='ignore')) break # Don't repeat bad HTML coding with several title marks httpout.write("\n\n") if AUTOWIDTH: httpout.write("\n") if ISMAP == "true": httpout.write("" "\"wrp-render\"\n" "\n" % (WebkitRenderer.req_map, WebkitRenderer.req_jpg)) mapfile = StringIO.StringIO() mapfile.write("default %s\n" % (web_url)) else: httpout.write("\"wrp-render\"\n" "\n" % (WebkitRenderer.req_jpg)) for x in frame.findAllElements('a'): turl = QUrl(web_url).resolved(QUrl(x.attribute('href'))).toString() xmin, ymin, xmax, ymax = x.geometry().getCoords() if ISMAP == "true": mapfile.write("rect %s %i,%i %i,%i\n".decode('utf-8', errors='ignore') % (turl, xmin, ymin, xmax, ymax)) else: httpout.write("\"%s\"\n".decode('utf-8', errors='ignore') % (xmin, ymin, xmax, ymax, turl, turl)) if ISMAP != "true": httpout.write("\n") httpout.write("\n\n") if ISMAP == "true": RENDERS[WebkitRenderer.req_map] = mapfile return image def _load_page(self, url, width, height, timeout): """ This method implements the logic for retrieving and displaying the requested page. """ # This is an event-based application. So we have to wait until # "loadFinished(bool)" raised. cancelAt = time.time() + timeout self.__loading = True self.__loadingResult = False # Default self._page.mainFrame().load(QUrl(url)) while self.__loading: if timeout > 0 and time.time() >= cancelAt: raise RuntimeError("Request timed out on %s" % url) while QApplication.hasPendingEvents() and self.__loading: QCoreApplication.processEvents() if self.logger: self.logger.debug("Processing result") if self.__loading_result == False: if self.logger: self.logger.warning("Failed to load %s" % url) # Set initial viewport (the size of the "window") size = self._page.mainFrame().contentsSize() if self.logger: self.logger.debug("contentsSize: %s", size) if width > 0: size.setWidth(width) if height > 0: size.setHeight(height) self._window.resize(size) def _on_each_reply(self, reply): """Logs each requested uri""" self.logger.debug("Received %s" % (reply.url().toString())) # Eventhandler for "loadStarted()" signal def _on_load_started(self): """Slot that sets the '__loading' property to true.""" if self.logger: self.logger.debug("loading started") self.__loading = True # Eventhandler for "loadFinished(bool)" signal def _on_load_finished(self, result): """Slot that sets the '__loading' property to false and stores the result code in '__loading_result'. """ if self.logger: self.logger.debug("loading finished with result %s", result) self.__loading = False self.__loading_result = result # Eventhandler for "sslErrors(QNetworkReply *,const QList&)" signal def _on_ssl_errors(self, reply, errors): """Slot that writes SSL warnings into the log but ignores them.""" for e in errors: if self.logger: self.logger.warn("SSL: " + e.errorString()) reply.ignoreSslErrors() class CustomWebPage(QWebPage): def __init__(self, **kwargs): super(CustomWebPage, self).__init__() self.logger = kwargs.get('logger', None) def javaScriptAlert(self, frame, message): if self.logger: self.logger.debug('Alert: %s', message) def javaScriptConfirm(self, frame, message): if self.logger: self.logger.debug('Confirm: %s', message) return False def javaScriptPrompt(self, frame, message, default, result): """This function is called whenever a JavaScript program running inside frame tries to prompt the user for input. The program may provide an optional message, msg, as well as a default value for the input in defaultValue. If the prompt was cancelled by the user the implementation should return false; otherwise the result should be written to result and true should be returned. If the prompt was not cancelled by the user, the implementation should return true and the result string must not be null. """ if self.logger: self.logger.debug('Prompt: %s (%s)' % (message, default)) return False def shouldInterruptJavaScript(self): """This function is called when a JavaScript program is running for a long period of time. If the user wanted to stop the JavaScript the implementation should return true; otherwise false. """ if self.logger: self.logger.debug("WebKit ask to interrupt JavaScript") return True #=============================================================================== def init_qtgui(display=None, style=None, qtargs=None): """Initiates the QApplication environment using the given args.""" if QApplication.instance(): logger.debug("QApplication has already been instantiated. \ Ignoring given arguments and returning existing QApplication.") return QApplication.instance() qtargs2 = [sys.argv[0]] if display: qtargs2.append('-display') qtargs2.append(display) # Also export DISPLAY var as this may be used # by flash plugin os.environ["DISPLAY"] = display if style: qtargs2.append('-style') qtargs2.append(style) qtargs2.extend(qtargs or []) return QApplication(qtargs2) # Technically, this is a QtGui application, because QWebPage requires it # to be. But because we will have no user interaction, and rendering can # not start before 'app.exec_()' is called, we have to trigger our "main" # by a timer event. def __main_qt(): # Render the page. # If this method times out or loading failed, a # RuntimeException is thrown try: while True: req = REQ.get() WebkitRenderer.httpout = req[0] WebkitRenderer.req_url = req[1] WebkitRenderer.req_jpg = req[2] WebkitRenderer.req_map = req[3] if WebkitRenderer.req_url == "http://wrp.stop/" or WebkitRenderer.req_url == "http://www.wrp.stop/": print ">>> Terminate Request Received" QApplication.exit(0) break # Initialize WebkitRenderer object renderer = WebkitRenderer() renderer.logger = logger renderer.width = WIDTH renderer.height = HEIGHT renderer.timeout = 60 renderer.wait = WAIT renderer.grabWholeWindow = False image = renderer.render(WebkitRenderer.req_url) qBuffer = QBuffer() image.save(qBuffer, 'jpg', QUALITY) output = StringIO.StringIO() output.write(qBuffer.buffer().data()) RENDERS[req[2]] = output del renderer print ">>> done: %s [%d kb]..." % (WebkitRenderer.req_jpg, output.len/1024) RESP.put('') QApplication.exit(0) except RuntimeError, e: logger.error("main: %s" % e) print >> sys.stderr, e QApplication.exit(1) ###################### ### macOS CODEPATH ### ###################### elif sys.platform == "darwin": import Foundation import WebKit import AppKit import objc class AppDelegate(Foundation.NSObject): # what happens when the app starts up def applicationDidFinishLaunching_(self, aNotification): webview = aNotification.object().windows()[0].contentView() webview.frameLoadDelegate().getURL(webview) class WebkitLoad(Foundation.NSObject, WebKit.protocols.WebFrameLoadDelegate): # what happens if something goes wrong while loading def webView_didFailLoadWithError_forFrame_(self, webview, error, frame): if error.code() == Foundation.NSURLErrorCancelled: return print " ... something went wrong 1: " + error.localizedDescription() AppKit.NSApplication.sharedApplication().terminate_(None) def webView_didFailProvisionalLoadWithError_forFrame_(self, webview, error, frame): if error.code() == Foundation.NSURLErrorCancelled: return print " ... something went wrong 2: " + error.localizedDescription() AppKit.NSApplication.sharedApplication().terminate_(None) def getURL(self, webview): req = REQ.get() WebkitLoad.httpout = req[0] WebkitLoad.req_url = req[1] WebkitLoad.req_gif = req[2] WebkitLoad.req_map = req[3] if WebkitLoad.req_url == "http://wrp.stop/" or WebkitLoad.req_url == "http://www.wrp.stop/": print ">>> Terminate Request Received" AppKit.NSApplication.sharedApplication().terminate_(None) nsurl = Foundation.NSURL.URLWithString_(WebkitLoad.req_url) if not (nsurl and nsurl.scheme()): nsurl = Foundation.NSURL.alloc().initFileURLWithPath_(WebkitLoad.req_url) nsurl = nsurl.absoluteURL() Foundation.NSURLRequest.setAllowsAnyHTTPSCertificate_forHost_(objc.YES, nsurl.host()) self.resetWebview(webview) webview.mainFrame().loadRequest_(Foundation.NSURLRequest.requestWithURL_(nsurl)) if not webview.mainFrame().provisionalDataSource(): print " ... not a proper url?" RESP.put('') self.getURL(webview) def resetWebview(self, webview): rect = Foundation.NSMakeRect(0, 0, WIDTH, HEIGHT) webview.window().setContentSize_((WIDTH, HEIGHT)) webview.setFrame_(rect) def captureView(self, view): view.window().display() view.window().setContentSize_(view.bounds().size) view.setFrame_(view.bounds()) if hasattr(view, "bitmapImageRepForCachingDisplayInRect_"): bitmapdata = view.bitmapImageRepForCachingDisplayInRect_(view.bounds()) view.cacheDisplayInRect_toBitmapImageRep_(view.bounds(), bitmapdata) else: view.lockFocus() bitmapdata = AppKit.NSBitmapImageRep.alloc() bitmapdata.initWithFocusedViewRect_(view.bounds()) view.unlockFocus() return bitmapdata # what happens when the page has finished loading def webView_didFinishLoadForFrame_(self, webview, frame): # don't care about subframes if frame == webview.mainFrame(): view = frame.frameView().documentView() output = StringIO.StringIO() output.write(self.captureView(view).representationUsingType_properties_( AppKit.NSGIFFileType, None)) RENDERS[WebkitLoad.req_gif] = output # url of the rendered page web_url = frame.dataSource().initialRequest().URL().absoluteString() httpout = WebkitLoad.httpout httpout.write("\n" % (__version__)) httpout.write("\n" % (WebkitLoad.req_url, web_url)) # Get title httpout.write("") for ttl in frame.findAllElements('title'): httpout.write((u"%s" % ttl.toPlainText()).encode('utf-8', errors='ignore')) break # Don't repeat bad HTML coding with several title marks httpout.write("\n\n") if AUTOWIDTH: httpout.write("\n") if ISMAP == "true": httpout.write("" "\"wrp-render\"\n" "\n" % (WebkitLoad.req_map, WebkitLoad.req_gif)) mapfile = StringIO.StringIO() mapfile.write("default %s\n" % (web_url)) else: httpout.write("\"wrp-render\"\n" "\n" % (WebkitLoad.req_gif)) domdocument = frame.DOMDocument() domnodelist = domdocument.getElementsByTagName_('A') i = 0 while i < domnodelist.length(): turl = domnodelist.item_(i).valueForKey_('href') #TODO: crashes? validate url? insert web_url if wrong? myrect = domnodelist.item_(i).boundingBox() xmin = Foundation.NSMinX(myrect) ymin = Foundation.NSMinY(myrect) xmax = Foundation.NSMaxX(myrect) ymax = Foundation.NSMaxY(myrect) if ISMAP == "true": mapfile.write("rect %s %i,%i %i,%i\n".decode('utf-8', errors='ignore') % (turl, xmin, ymin, xmax, ymax)) else: httpout.write("\"%s\"\n".decode('utf-8', errors='ignore') % (xmin, ymin, xmax, ymax, turl, turl)) i += 1 if ISMAP != "true": httpout.write("\n") httpout.write("\n\n") if ISMAP == "true": RENDERS[WebkitLoad.req_map] = mapfile # Return to Proxy thread and Loop... RESP.put('') self.getURL(webview) def main_cocoa(): # Launch NS Application AppKit.NSApplicationLoad() app = AppKit.NSApplication.sharedApplication() delegate = AppDelegate.alloc().init() AppKit.NSApp().setDelegate_(delegate) AppKit.NSBundle.mainBundle().infoDictionary()['NSAppTransportSecurity'] = \ dict(NSAllowsArbitraryLoads=True) rect = Foundation.NSMakeRect(-16000, -16000, 100, 100) win = AppKit.NSWindow.alloc() win.initWithContentRect_styleMask_backing_defer_(rect, AppKit.NSBorderlessWindowMask, 2, 0) webview = WebKit.WebView.alloc() webview.initWithFrame_(rect) webview.mainFrame().frameView().setAllowsScrolling_(objc.NO) webkit_version = Foundation.NSBundle.bundleForClass_(WebKit.WebView). \ objectForInfoDictionaryKey_(WebKit.kCFBundleVersionKey)[1:] webview.setApplicationNameForUserAgent_("Like-Version/6.0 Safari/%s wrp/%s" % (webkit_version, __version__)) win.setContentView_(webview) loaddelegate = WebkitLoad.alloc().init() loaddelegate.options = [""] webview.setFrameLoadDelegate_(loaddelegate) app.run() ####################### ### COMMON CODEPATH ### ####################### class Proxy(SimpleHTTPServer.SimpleHTTPRequestHandler): def do_GET(self): req_url = self.path httpout = self.wfile gif_re = re.match(r"http://(wrp-\d+\.gif).*", req_url) map_re = re.match(r"http://(wrp-\d+\.map).*?(\d+),(\d+)", req_url) jpg_re = re.match(r"http://(wrp-\d+\.jpg).*", req_url) wid_re = re.match(r"http://(width-[0-9]+-px\.jpg).*", req_url) # Serve Rendered GIF if gif_re: img = gif_re.group(1) print ">>> request for rendered gif image... %s [%d kb]" \ % (img, RENDERS[img].len/1024) self.send_response(200, 'OK') self.send_header('Content-type', 'image/gif') self.end_headers() httpout.write(RENDERS[img].getvalue()) del RENDERS[img] elif jpg_re: img = jpg_re.group(1) print ">>> request for rendered jpg image... %s [%d kb]" \ % (img, RENDERS[img].len/1024) self.send_response(200, 'OK') self.send_header('Content-type', 'image/jpeg') self.end_headers() httpout.write(RENDERS[img].getvalue()) del RENDERS[img] elif wid_re: global WIDTH try: wid = req_url.split("-") WIDTH = int(wid[1]) print ">>> width request: %d" % WIDTH except: print ">>> width request error" % WIDTH self.send_error(404, "Width request") self.end_headers() # Process ISMAP Request elif map_re: map = map_re.group(1) req_x = int(map_re.group(2)) req_y = int(map_re.group(3)) print ">>> ISMAP request... %s [%d,%d] " % (map, req_x, req_y) mapf = RENDERS[map] mapf.seek(0) goto_url = "none" for line in mapf.readlines(): if re.match(r"(\S+)", line).group(1) == "default": default_url = re.match(r"\S+\s+(\S+)", line).group(1) elif re.match(r"(\S+)", line).group(1) == "rect": try: rect = re.match(r"(\S+)\s+(\S+)\s+(\d+),(\d+)\s+(\d+),(\d+)", line) min_x = int(rect.group(3)) min_y = int(rect.group(4)) max_x = int(rect.group(5)) max_y = int(rect.group(6)) if (req_x >= min_x) and \ (req_x <= max_x) and \ (req_y >= min_y) and \ (req_y <= max_y): goto_url = rect.group(2) except AttributeError: pass if goto_url == "none": goto_url = default_url print ">>> ISMAP redirect: %s\n" % (goto_url) self.send_response(302, "Found") self.send_header("Location", goto_url) self.send_header("Content-type", "text/html") self.end_headers() httpout.write("%s\n" % (goto_url, goto_url)) # Process a web page request and generate image else: print ">>> URL request... " + req_url if req_url == "http://wrp.stop/" or req_url == "http://www.wrp.stop/": REQ.put((httpout, req_url, "", "")) RESP.get() else: reqst = urllib.urlopen(req_url) if reqst.info().type == "text/html" or reqst.info().type == "application/xhtml+xml": # If an error occurs, send error headers to the requester if reqst.getcode() >= 400: self.send_response(reqst.getcode()) for hdr in reqst.info(): self.send_header(hdr, reqst.info()[hdr]) self.end_headers() else: self.send_response(200, 'OK') self.send_header('Content-type', 'text/html') self.end_headers() rnd = random.randrange(0, 1000) if sys.platform == "linux" or sys.platform == "linux2": "wrp-%s.jpg" % (rnd) "wrp-%s.map" % (rnd) # To thread REQ.put((httpout, req_url, "wrp-%s.jpg" % (rnd), "wrp-%s.map" % (rnd))) # Wait for completition RESP.get() elif sys.platform == "darwin": "wrp-%s.gif" % (rnd) "wrp-%s.map" % (rnd) # To WebKit Thread REQ.put((httpout, req_url, "wrp-%s.gif" % (rnd), "wrp-%s.map" % (rnd))) # Wait for completition RESP.get() # If the requested file is not HTML or XHTML, just return it as is. else: self.send_response(reqst.getcode()) for hdr in reqst.info(): self.send_header(hdr, reqst.info()[hdr]) self.end_headers() httpout.write(reqst.read()) def run_proxy(): httpd = SocketServer.TCPServer(('', PORT), Proxy) print "Web Rendering Proxy v%s serving at port: %s" % (__version__, PORT) while 1: httpd.serve_forever() def main(): # Launch Proxy Thread threading.Thread(target=run_proxy).start() if sys.platform == "linux" or sys.platform == "linux2": import signal try: import PyQt5.QtCore except ImportError: import PyQt4.QtCore # Initialize Qt-Application, but make this script # abortable via CTRL-C app = init_qtgui(display=None, style=None) signal.signal(signal.SIGINT, signal.SIG_DFL) QTimer.singleShot(0, __main_qt) sys.exit(app.exec_()) elif sys.platform == "darwin": main_cocoa() else: sys.exit("Unsupported platform: %s. Exiting." % sys.platform) if __name__ == '__main__': main()