#!/usr/bin/env python
"""
Copyright (c) 2005 Dustin Sallings <dustin@spy.net>
"""
import os
import sys
import shutil
import signal
import urllib2
class StatusHandler(urllib2.HTTPDefaultErrorHandler):
def http_error_default(self, req, fp, code, msg, headers):
result=urllib2.HTTPError(req.get_full_url(), code, msg, headers, fp)
result.code=code
return result
def getEtag(wantedfile):
rv=None
etf=wantedfile + ".etag"
if os.path.exists(etf):
f=open(etf)
rv=f.read().strip()
f.close()
return rv
def saveEtag(wantedfile, etag):
if etag is not None:
etf=wantedfile + ".etag"
tmpfile=etf + ".tmp"
f=open(tmpfile, "w")
f.write(etag)
f.close()
os.rename(tmpfile, etf)
def doUpdate(u, wantedfile):
tmpfile=wantedfile + ".tmp"
req=urllib2.Request(u)
etag=getEtag(wantedfile)
if etag is not None:
req.add_header('If-None-Match', etag);
opener=urllib2.build_opener(StatusHandler())
i=opener.open(req)
# This looks a little strange, but it gives me python 2.2 compatibility
# If the code attr doesn't exist, or it does and it's 200, then we update.
if not hasattr(i, 'code') or i.code == 200:
o=open(tmpfile, "w")
shutil.copyfileobj(i, o)
os.rename(tmpfile, wantedfile)
etag=i.info().getheader('ETag')
saveEtag(wantedfile, etag)
if __name__ == '__main__':
# You have thirty seconds to comply
signal.alarm(30)
wantedfile=sys.argv[2]
try:
doUpdate(sys.argv[1], wantedfile)
except:
sys.stderr.write("Error processing %s\n" % sys.argv[1])
raise
