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 not file:
  25             file = os.path.join(os.environ['HOME'], ".netrc")
  26         fp = open(file)
  27         self.hosts = {}
  28         self.macros = {}
  29         lexer = shlex.shlex(fp)
  30         # Allows @ in hostnames.  Not a big deal...
  31         lexer.wordchars = lexer.wordchars + '.-@'
  32         while 1:
  33             # Look for a machine, default, or macdef top-level keyword
  34             toplevel = tt = lexer.get_token()
  35             if not tt:
  36                 break
  37             elif tt == 'machine':
  38                 entryname = lexer.get_token()
  39             elif tt == 'default':
  40                 entryname = 'default'
  41             elif tt == 'macdef':                # Just skip to end of macdefs
  42                 entryname = lexer.get_token()
  43                 self.macros[entryname] = []
  44                 lexer.whitepace = ' \t'
  45                 while 1:
  46                     line = lexer.instream.readline()
  47                     if not line or line == '\012' and tt == '\012':
  48                         lexer.whitepace = ' \t\r\n'
  49                         break
  50                     tt = line
  51                     self.macros[entryname].append(line)
  52             else:
  53                 raise NetrcParseError(
  54                     "bad toplevel token %r" % tt, file, lexer.lineno)
  55
  56             # We're looking at start of an entry for a named machine or default.
  57             if toplevel == 'machine':
  58                 login = account = password = None
  59                 self.hosts[entryname] = {}
  60             while 1:
  61                 tt = lexer.get_token()
  62                 if tt=='' or tt == 'machine' or tt == 'default' or tt == 'macdef':
  63                     if toplevel == 'macdef':
  64                         break
  65                     elif login and password:
  66                         self.hosts[entryname] = (login, account, password)
  67                         lexer.push_token(tt)
  68                         break
  69                     else:
  70                         raise NetrcParseError(
  71                             "malformed %s entry %s terminated by %s"
  72                             % (toplevel, entryname, repr(tt)),
  73                             file, lexer.lineno)
  74                 elif tt == 'login' or tt == 'user':
  75                     login = lexer.get_token()
  76                 elif tt == 'account':
  77                     account = lexer.get_token()
  78                 elif tt == 'password':
  79                     password = lexer.get_token()
  80                 else:
  81                     raise NetrcParseError("bad follower token %r" % tt,
  82                                           file, lexer.lineno)
  83
  84     def authenticators(self, host):
  85         """Return a (user, account, password) tuple for given host."""
  86         if self.hosts.has_key(host):
  87             return self.hosts[host]
  88         elif self.hosts.has_key('default'):
  89             return self.hosts['default']
  90         else:
  91             return None
  92
  93     def __repr__(self):
  94         """Dump the class data in the format of a .netrc file."""
  95         rep = ""
  96         for host in self.hosts.keys():
  97             attrs = self.hosts[host]
  98             rep = rep + "machine "+ host + "\n\tlogin " + repr(attrs[0]) + "\n"
  99             if attrs[1]:
 100                 rep = rep + "account " + repr(attrs[1])
 101             rep = rep + "\tpassword " + repr(attrs[2]) + "\n"
 102         for macro in self.macros.keys():
 103             rep = rep + "macdef " + macro + "\n"
 104             for line in self.macros[macro]:
 105                 rep = rep + line
 106             rep = rep + "\n"
 107         return rep
 108
 109 if __name__ == '__main__':
 110     print netrc()