Lib/getpass.py

Source:

cpython 3.14 @ ab2d84fe1023/Lib/getpass.py ↗

getpass.getpass(prompt) reads a password without terminal echo. It uses /dev/tty directly when available so that stdin can be redirected without exposing the password.

Map

Lines	Symbol	Role
1-40	getpass	Main entry: try /dev/tty, fall back to input()
41-100	unix_getpass	Open /dev/tty, disable echo via termios, read, restore
101-140	win_getpass	Windows: use msvcrt.getwch loop
141-180	getuser	Return login name from env or pwd

Reading

unix_getpass

# CPython: Lib/getpass.py:58 unix_getpass
def unix_getpass(prompt='Password: ', stream=None):
    """Prompt for a password, with echo disabled."""
    fd = None
    tty = None
    try:
        # Prefer /dev/tty so we can still prompt even if stdin is redirected
        try:
            fd = os.open('/dev/tty', os.O_RDWR | os.O_NOCTTY)
            tty = io.open(fd, mode='r+', closefd=False)
        except OSError:
            tty = stream or sys.stderr

        old = termios.tcgetattr(fd)
        new = old[:]
        new[3] &= ~termios.ECHO           # turn off echo
        new[3] |= termios.ECHONL          # but keep newline echo
        try:
            termios.tcsetattr(fd, termios.TCSADRAIN, new)
            passwd = tty.readline()
        finally:
            termios.tcsetattr(fd, termios.TCSADRAIN, old)  # always restore
    finally:
        if tty is not None and tty is not stream:
            tty.close()
        if fd is not None:
            os.close(fd)
    return passwd.rstrip('\n')

getuser

# CPython: Lib/getpass.py:165 getuser
def getuser():
    """Return the login name of the current user."""
    for name in ('LOGNAME', 'USER', 'LNAME', 'USERNAME'):
        user = os.environ.get(name)
        if user:
            return user
    # Last resort: look up in pwd database
    import pwd
    return pwd.getpwuid(os.getuid()).pw_name

gopy notes

getpass is pure Python. unix_getpass uses termios.tcgetattr/tcsetattr (gopy module/termios) and os.open/os.close (gopy module/os). getuser uses pwd.getpwuid (gopy module/pwd).