Prompt the user for a password without echoing. The user is prompted using the
string *prompt*, which defaults to ``'Password: '``. On Unix, the prompt is
- written to the file-like object *stream*, which defaults to ``sys.stdout`` (this
- argument is ignored on Windows).
+ written to the file-like object *stream*. *stream* defaults to the
+ controlling terminal (/dev/tty) or if that is unavailable to ``sys.stderr``
+ (this argument is ignored on Windows).
+
+ If echo free input is unavailable getpass() falls back to printing
+ a warning message to *stream* and reading from ``sys.stdin`` and
+ issuing a :exc:`GetPassWarning`.
Availability: Macintosh, Unix, Windows.
.. versionchanged:: 2.5
The *stream* parameter was added.
+ .. versionchanged:: 2.6
+ On Unix it defaults to using /dev/tty before falling back
+ to ``sys.stdin`` and ``sys.stderr``.
+ .. note::
+ If you call getpass from within idle, the input may be done in the
+ terminal you launched idle from rather than the idle window itself.
+
+
+.. exception:: GetPassWarning
+
+ A :exc:`UserWarning` subclass issued when password input may be echoed.
.. function:: getuser()
"""Utilities to get a password and/or the current user name.
-getpass(prompt) - prompt for a password, with echo turned off
-getuser() - get the user name from the environment or password database
+getpass(prompt[, stream]) - Prompt for a password, with echo turned off.
+getuser() - Get the user name from the environment or password database.
+
+GetPassWarning - This UserWarning is issued when getpass() cannot prevent
+ echoing of the password contents while reading.
On Windows, the msvcrt module will be used.
On the Mac EasyDialogs.AskPassword is used, if available.
# Authors: Piers Lauder (original)
# Guido van Rossum (Windows support and cleanup)
+# Gregory P. Smith (tty support & GetPassWarning)
-import sys
-
-__all__ = ["getpass","getuser"]
+import os, sys, warnings
-def unix_getpass(prompt='Password: ', stream=None):
- """Prompt for a password, with echo turned off.
- The prompt is written on stream, by default stdout.
+__all__ = ["getpass","getuser","GetPassWarning"]
- Restore terminal settings at end.
- """
- if stream is None:
- stream = sys.stdout
- if not sys.stdin.isatty():
- print >>sys.stderr, "Warning: sys.stdin is not a tty."
- return default_getpass(prompt)
+class GetPassWarning(UserWarning): pass
- try:
- fd = sys.stdin.fileno()
- except:
- return default_getpass(prompt)
- old = termios.tcgetattr(fd) # a copy to save
- new = old[:]
+def unix_getpass(prompt='Password: ', stream=None):
+ """Prompt for a password, with echo turned off.
- new[3] = new[3] & ~termios.ECHO # 3 == 'lflags'
+ Args:
+ prompt: Written on stream to ask for the input. Default: 'Password: '
+ stream: A writable file object to display the prompt. Defaults to
+ the tty. If no tty is available defaults to sys.stderr.
+ Returns:
+ The seKr3t input.
+ Raises:
+ EOFError: If our input tty or stdin was closed.
+ GetPassWarning: When we were unable to turn echo off on the input.
+
+ Always restores terminal settings before returning.
+ """
+ fd = None
+ tty = None
try:
- termios.tcsetattr(fd, termios.TCSADRAIN, new)
- passwd = _raw_input(prompt, stream)
- finally:
- termios.tcsetattr(fd, termios.TCSADRAIN, old)
+ # Always try reading and writing directly on the tty first.
+ fd = os.open('/dev/tty', os.O_RDWR|os.O_NOCTTY)
+ tty = os.fdopen(fd, 'w+', 1)
+ input = tty
+ if not stream:
+ stream = tty
+ except EnvironmentError, e:
+ # If that fails, see if stdin can be controlled.
+ try:
+ fd = sys.stdin.fileno()
+ except:
+ passwd = fallback_getpass(prompt, stream)
+ input = sys.stdin
+ if not stream:
+ stream = sys.stderr
+
+ if fd is not None:
+ passwd = None
+ try:
+ old = termios.tcgetattr(fd) # a copy to save
+ new = old[:]
+ new[3] &= ~termios.ECHO # 3 == 'lflags'
+ try:
+ termios.tcsetattr(fd, termios.TCSADRAIN, new)
+ passwd = _raw_input(prompt, stream, input=input)
+ finally:
+ termios.tcsetattr(fd, termios.TCSADRAIN, old)
+ except termios.error, e:
+ if passwd is not None:
+ # _raw_input succeeded. The final tcsetattr failed. Reraise
+ # instead of leaving the terminal in an unknown state.
+ raise
+ # We can't control the tty or stdin. Give up and use normal IO.
+ # fallback_getpass() raises an appropriate warning.
+ del input, tty # clean up unused file objects before blocking
+ passwd = fallback_getpass(prompt, stream)
stream.write('\n')
return passwd
def win_getpass(prompt='Password: ', stream=None):
"""Prompt for password with echo off, using Windows getch()."""
if sys.stdin is not sys.__stdin__:
- return default_getpass(prompt, stream)
+ return fallback_getpass(prompt, stream)
import msvcrt
for c in prompt:
msvcrt.putch(c)
return pw
-def default_getpass(prompt='Password: ', stream=None):
- print >>sys.stderr, "Warning: Problem with getpass. Passwords may be echoed."
+def fallback_getpass(prompt='Password: ', stream=None):
+ warnings.warn("Can not control echo on the terminal.", GetPassWarning,
+ stacklevel=2)
+ if not stream:
+ stream = sys.stderr
+ print >>stream, "Warning: Password input may be echoed."
return _raw_input(prompt, stream)
-def _raw_input(prompt="", stream=None):
+def _raw_input(prompt="", stream=None, input=None):
# A raw_input() replacement that doesn't save the string in the
# GNU readline history.
- if stream is None:
- stream = sys.stdout
+ if not stream:
+ stream = sys.stderr
+ if not input:
+ input = sys.stdin
prompt = str(prompt)
if prompt:
stream.write(prompt)
- line = sys.stdin.readline()
+ stream.flush()
+ line = input.readline()
if not line:
raise EOFError
if line[-1] == '\n':
try:
from EasyDialogs import AskPassword
except ImportError:
- getpass = default_getpass
+ getpass = fallback_getpass
else:
getpass = AskPassword
else:
projects / python / commitdiff