Lib/netrc.py

   1 """An object-oriented interface to .netrc files."""
   2
   3 # Module and documentation by Eric S. Raymond, 21 Dec 1998
   4
   5 import os, shlex
   6
   7 __all__ = ["netrc", "NetrcParseError"]
   8
   9
  10 class NetrcParseError(Exception):
  11     """Exception raised on syntax errors in the .netrc file."""
  12     def __init__(self, msg, filename=None, lineno=None):
  13         self.filename = filename
  14         self.lineno = lineno
  15         self.msg = msg
  16         Exception.__init__(self, msg)
  17
  18     def __str__(self):
  19         return "%s (%s, line %s)" % (self.msg, self.filename, self.lineno)
  20
  21
  22 class netrc:
  23     def __init__(self, file=None):
  24         if file is None:
  25             try:
  26                 file = os.path.join(os.environ['HOME'], ".netrc")
  27             except KeyError:
  28                 raise IOError("Could not find .netrc: $HOME is not set")
  29         self.hosts = {}
  30         self.macros = {}
  31         with open(file) as fp:
  32             self._parse(file, fp)
  33
  34     def _parse(self, file, fp):
  35         lexer = shlex.shlex(fp)
  36         lexer.wordchars += r"""!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~"""
  37         while 1:
  38             # Look for a machine, default, or macdef top-level keyword
  39             toplevel = tt = lexer.get_token()
  40             if not tt:
  41                 break
  42             elif tt == 'machine':
  43                 entryname = lexer.get_token()
  44             elif tt == 'default':
  45                 entryname = 'default'
  46             elif tt == 'macdef':                # Just skip to end of macdefs
  47                 entryname = lexer.get_token()
  48                 self.macros[entryname] = []
  49                 lexer.whitespace = ' \t'
  50                 while 1:
  51                     line = lexer.instream.readline()
  52                     if not line or line == '\012':
  53                         lexer.whitespace = ' \t\r\n'
  54                         break
  55                     self.macros[entryname].append(line)
  56                 continue
  57             else:
  58                 raise NetrcParseError(
  59                     "bad toplevel token %r" % tt, file, lexer.lineno)
  60
  61             # We're looking at start of an entry for a named machine or default.
  62             login = ''
  63             account = password = None
  64             self.hosts[entryname] = {}
  65             while 1:
  66                 tt = lexer.get_token()
  67                 if (tt=='' or tt == 'machine' or
  68                     tt == 'default' or tt =='macdef'):
  69                     if password:
  70                         self.hosts[entryname] = (login, account, password)
  71                         lexer.push_token(tt)
  72                         break
  73                     else:
  74                         raise NetrcParseError(
  75                             "malformed %s entry %s terminated by %s"
  76                             % (toplevel, entryname, repr(tt)),
  77                             file, lexer.lineno)
  78                 elif tt == 'login' or tt == 'user':
  79                     login = lexer.get_token()
  80                 elif tt == 'account':
  81                     account = lexer.get_token()
  82                 elif tt == 'password':
  83                     password = lexer.get_token()
  84                 else:
  85                     raise NetrcParseError("bad follower token %r" % tt,
  86                                           file, lexer.lineno)
  87
  88     def authenticators(self, host):
  89         """Return a (user, account, password) tuple for given host."""
  90         if host in self.hosts:
  91             return self.hosts[host]
  92         elif 'default' in self.hosts:
  93             return self.hosts['default']
  94         else:
  95             return None
  96
  97     def __repr__(self):
  98         """Dump the class data in the format of a .netrc file."""
  99         rep = ""
 100         for host in self.hosts.keys():
 101             attrs = self.hosts[host]
 102             rep = rep + "machine "+ host + "\n\tlogin " + repr(attrs[0]) + "\n"
 103             if attrs[1]:
 104                 rep = rep + "account " + repr(attrs[1])
 105             rep = rep + "\tpassword " + repr(attrs[2]) + "\n"
 106         for macro in self.macros.keys():
 107             rep = rep + "macdef " + macro + "\n"
 108             for line in self.macros[macro]:
 109                 rep = rep + line
 110             rep = rep + "\n"
 111         return rep
 112
 113 if __name__ == '__main__':
 114     print netrc()