zeroinstall/injector/_download_child.py

   1 # Copyright (C) 2010, Thomas Leonard
   2 # See the README file for details, or visit http://0install.net.
   3
   4 import sys, os
   5 sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.dirname(__file__))))
   6
   7 from zeroinstall import _
   8
   9 # NB: duplicated in download.py
  10 RESULT_OK = 0
  11 RESULT_FAILED = 1
  12 RESULT_NOT_MODIFIED = 2
  13
  14 def _download_as_child(url, if_modified_since):
  15         from httplib import HTTPException
  16         from urllib2 import urlopen, Request, HTTPError, URLError
  17         try:
  18                 #print "Child downloading", url
  19                 if url.startswith('http:') or url.startswith('https:') or url.startswith('ftp:'):
  20                         req = Request(url)
  21                         if url.startswith('http:') and if_modified_since:
  22                                 req.add_header('If-Modified-Since', if_modified_since)
  23                         src = urlopen(req)
  24                 else:
  25                         raise Exception(_('Unsupported URL protocol in: %s') % url)
  26
  27                 try:
  28                         sock = src.fp._sock
  29                 except AttributeError:
  30                         sock = src.fp.fp._sock  # Python 2.5 on FreeBSD
  31                 while True:
  32                         data = sock.recv(256)
  33                         if not data: break
  34                         os.write(1, data)
  35
  36                 sys.exit(RESULT_OK)
  37         except (HTTPError, URLError, HTTPException) as ex:
  38                 if isinstance(ex, HTTPError) and ex.code == 304: # Not modified
  39                         sys.exit(RESULT_NOT_MODIFIED)
  40                 print >>sys.stderr, "Error downloading '" + url + "': " + (str(ex) or str(ex.__class__.__name__))
  41                 sys.exit(RESULT_FAILED)
  42
  43 if __name__ == '__main__':
  44         assert (len(sys.argv) == 2) or (len(sys.argv) == 3), "Usage: download URL [If-Modified-Since-Date], not %s" % sys.argv
  45         if len(sys.argv) >= 3:
  46                 if_modified_since_date = sys.argv[2]
  47         else:
  48                 if_modified_since_date = None
  49         _download_as_child(sys.argv[1], if_modified_since_date)