netrc.py
"""An object-oriented interface to .netrc files."""
# Module and documentation by Eric S. Raymond, 21 Dec 1998
import os, shlex, stat
__all__ = ["netrc", "NetrcParseError"]
class NetrcParseError(Exception):
"""Exception raised on syntax errors in the .netrc file."""
def __init__(self, msg, filename=None, lineno=None):
self.filename = filename
self.lineno = lineno
self.msg = msg
Exception.__init__(self, msg)
def __str__(self):
return "%s (%s, line %s)" % (self.msg, self.filename, self.lineno)
class netrc:
def __init__(self, file=None):
default_netrc = file is None
if file is None:
file = os.path.join(os.path.expanduser("~"), ".netrc")
self.hosts = {}
self.macros = {}
with open(file) as fp:
self._parse(file, fp, default_netrc)
def _parse(self, file, fp, default_netrc):
lexer = shlex.shlex(fp)
lexer.wordchars += r"""!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~"""
lexer.commenters = lexer.commenters.replace('#', '')
while 1:
# Look for a machine, default, or macdef top-level keyword
saved_lineno = lexer.lineno
toplevel = tt = lexer.get_token()
if not tt:
break
elif tt[0] == '#':
if lexer.lineno == saved_lineno and len(tt) == 1:
lexer.instream.readline()
continue
elif tt == 'machine':
entryname = lexer.get_token()
elif tt == 'default':
entryname = 'default'
elif tt == 'macdef': # Just skip to end of macdefs
entryname = lexer.get_token()
self.macros[entryname] = []
lexer.whitespace = ' \t'
while 1:
line = lexer.instream.readline()
if not line or line == '\012':
lexer.whitespace = ' \t\r\n'
break
self.macros[entryname].append(line)
continue
else:
raise NetrcParseError(
"bad toplevel token %r" % tt, file, lexer.lineno)
# We're looking at start of an entry for a named machine or default.
login = ''
account = password = None
self.hosts[entryname] = {}
while 1:
tt = lexer.get_token()
if (tt.startswith('#') or
tt in {'', 'machine', 'default', 'macdef'}):
if password:
self.hosts[entryname] = (login, account, password)
lexer.push_token(tt)
break
else:
raise NetrcParseError(
"malformed %s entry %s terminated by %s"
% (toplevel, entryname, repr(tt)),
file, lexer.lineno)
elif tt == 'login' or tt == 'user':
login = lexer.get_token()
elif tt == 'account':
account = lexer.get_token()
elif tt == 'password':
if os.name == 'posix' and default_netrc:
prop = os.fstat(fp.fileno())
if prop.st_uid != os.getuid():
import pwd
try:
fowner = pwd.getpwuid(prop.st_uid)[0]
except KeyError:
fowner = 'uid %s' % prop.st_uid
try:
user = pwd.getpwuid(os.getuid())[0]
except KeyError:
user = 'uid %s' % os.getuid()
raise NetrcParseError(
("~/.netrc file owner (%s) does not match"
" current user (%s)") % (fowner, user),
file, lexer.lineno)
if (prop.st_mode & (stat.S_IRWXG | stat.S_IRWXO)):
raise NetrcParseError(
"~/.netrc access too permissive: access"
" permissions must restrict access to only"
" the owner", file, lexer.lineno)
password = lexer.get_token()
else:
raise NetrcParseError("bad follower token %r" % tt,
file, lexer.lineno)
def authenticators(self, host):
"""Return a (user, account, password) tuple for given host."""
if host in self.hosts:
return self.hosts[host]
elif 'default' in self.hosts:
return self.hosts['default']
else:
return None
def __repr__(self):
"""Dump the class data in the format of a .netrc file."""
rep = ""
for host in self.hosts.keys():
attrs = self.hosts[host]
rep += f"machine {host}\n\tlogin {attrs[0]}\n"
if attrs[1]:
rep += f"\taccount {attrs[1]}\n"
rep += f"\tpassword {attrs[2]}\n"
for macro in self.macros.keys():
rep += f"macdef {macro}\n"
for line in self.macros[macro]:
rep += line
rep += "\n"
return rep
if __name__ == '__main__':
print(netrc())