cpython/Lib/getpass.py

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"""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
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)
"""
import sys
def unix_getpass(prompt='Password: '):
"""Prompt for a password, with echo turned off.
Restore terminal settings at end.
"""
try:
fd = sys.stdin.fileno()
except:
return default_getpass(prompt)
getpass = default_getpass
old = termios.tcgetattr(fd) # a copy to save
new = old[:]
new[3] = new[3] & ~TERMIOS.ECHO # 3 == 'lflags'
try:
termios.tcsetattr(fd, TERMIOS.TCSADRAIN, new)
passwd = _raw_input(prompt)
finally:
termios.tcsetattr(fd, TERMIOS.TCSADRAIN, old)
sys.stdout.write('\n')
return passwd
def win_getpass(prompt='Password: '):
"""Prompt for password with echo off, using Windows getch()."""
import msvcrt
for c in prompt:
msvcrt.putch(c)
pw = ""
while 1:
c = msvcrt.getch()
if c == '\r' or c == '\n':
break
if c == '\003':
raise KeyboardInterrupt
if c == '\b':
pw = pw[:-1]
else:
pw = pw + c
msvcrt.putch('\r')
msvcrt.putch('\n')
return pw
def default_getpass(prompt='Password: '):
print "Warning: Problem with getpass. Passwords may be echoed."
return _raw_input(prompt)
def _raw_input(prompt=""):
# A raw_input() replacement that doesn't save the string in the
# GNU readline history.
import sys
prompt = str(prompt)
if prompt:
sys.stdout.write(prompt)
line = sys.stdin.readline()
if not line:
raise EOFError
if line[-1] == '\n':
line = line[:-1]
return line
def getuser():
"""Get the username from the environment or password database.
First try various environment variables, then the password
database. This works on Windows as long as USERNAME is set.
"""
import os
for name in ('LOGNAME', 'USER', 'LNAME', 'USERNAME'):
user = os.environ.get(name)
if user:
return user
# If this fails, the exception will "explain" why
import pwd
return pwd.getpwuid(os.getuid())[0]
# Bind the name getpass to the appropriate function
try:
import termios, TERMIOS
except ImportError:
try:
import msvcrt
except ImportError:
try:
from EasyDialogs import AskPassword
except ImportError:
getpass = default_getpass
else:
getpass = AskPassword
else:
getpass = win_getpass
else:
getpass = unix_getpass