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