1 """Utilities to get a password and/or the current user name.

     2 

     3 getpass(prompt) - prompt for a password, with echo turned off

     4 getuser() - get the user name from the environment or password database

     5 

     6 On Windows, the msvcrt module will be used.

     7 On the Mac EasyDialogs.AskPassword is used, if available.

     8 

     9 """

    10 

    11 # Authors: Piers Lauder (original)

    12 #          Guido van Rossum (Windows support and cleanup)

    13 

    14 import sys

    15 

    16 __all__ = ["getpass","getuser"]

    17 

    18 def unix_getpass(prompt='Password: ', stream=None):

    19     """Prompt for a password, with echo turned off.

    20     The prompt is written on stream, by default stdout.

    21 

    22     Restore terminal settings at end.

    23     """

    24     if stream is None:

    25         stream = sys.stdout

    26 

    27     try:

    28         fd = sys.stdin.fileno()

    29     except:

    30         return default_getpass(prompt)

    31 

    32     old = termios.tcgetattr(fd)     # a copy to save

    33     new = old[:]

    34 

    35     new[3] = new[3] & ~termios.ECHO # 3 == 'lflags'

    36     try:

    37         termios.tcsetattr(fd, termios.TCSADRAIN, new)

    38         passwd = _raw_input(prompt, stream)

    39     finally:

    40         termios.tcsetattr(fd, termios.TCSADRAIN, old)

    41 

    42     stream.write('\n')

    43     return passwd

    44 

    45 

    46 def win_getpass(prompt='Password: ', stream=None):

    47     """Prompt for password with echo off, using Windows getch()."""

    48     if sys.stdin is not sys.__stdin__:

    49         return default_getpass(prompt, stream)

    50     import msvcrt

    51     for c in prompt:

    52         msvcrt.putch(c)

    53     pw = ""

    54     while 1:

    55         c = msvcrt.getch()

    56         if c == '\r' or c == '\n':

    57             break

    58         if c == '\003':

    59             raise KeyboardInterrupt

    60         if c == '\b':

    61             pw = pw[:-1]

    62         else:

    63             pw = pw + c

    64     msvcrt.putch('\r')

    65     msvcrt.putch('\n')

    66     return pw

    67 

    68 

    69 def default_getpass(prompt='Password: ', stream=None):

    70     print >>sys.stderr, "Warning: Problem with getpass. Passwords may be echoed."

    71     return _raw_input(prompt, stream)

    72 

    73 

    74 def _raw_input(prompt="", stream=None):

    75     # A raw_input() replacement that doesn't save the string in the

    76     # GNU readline history.

    77     if stream is None:

    78         stream = sys.stdout

    79     prompt = str(prompt)

    80     if prompt:

    81         stream.write(prompt)

    82     line = sys.stdin.readline()

    83     if not line:

    84         raise EOFError

    85     if line[-1] == '\n':

    86         line = line[:-1]

    87     return line

    88 

    89 

    90 def getuser():

    91     """Get the username from the environment or password database.

    92 

    93     First try various environment variables, then the password

    94     database.  This works on Windows as long as USERNAME is set.

    95 

    96     """

    97 

    98     import os

    99 

   100     for name in ('LOGNAME', 'USER', 'LNAME', 'USERNAME'):

   101         user = os.environ.get(name)

   102         if user:

   103             return user

   104 

   105     # If this fails, the exception will "explain" why

   106     import pwd

   107     return pwd.getpwuid(os.getuid())[0]

   108 

   109 # Bind the name getpass to the appropriate function

   110 try:

   111     import termios

   112     # it's possible there is an incompatible termios from the

   113     # McMillan Installer, make sure we have a UNIX-compatible termios

   114     termios.tcgetattr, termios.tcsetattr

   115 except (ImportError, AttributeError):

   116     try:

   117         import msvcrt

   118     except ImportError:

   119         try:

   120             from EasyDialogs import AskPassword

   121         except ImportError:

   122             getpass = default_getpass

   123         else:

   124             getpass = AskPassword

   125     else:

   126         getpass = win_getpass

   127 else:

   128     getpass = unix_getpass